Mitigating urban heat pains through nature-based cool pavement in extremely hot climates

Mitigating urban heat pains through nature-based cool pavement in extremely hot climates ☆ Paulo García-Melgar a , Paz Montero-Guti´ errez a , María del Carmen Guerrero Delgado a,* , Alberto Cerezo Narv´ aez b , Jos´ e S´ anchez Ramos a , Servando ´ Alvarez Domínguez a a Grupo Termotecnia, Escuela Superior de Ingeniería, University of Seville, Spain b Grupo Termotecnia, Escuela Superior de Ingeniería, University of Cadiz, Spain ARTICLE INFO Keywords: Urban overheating Nature based solutions Passive cooling Cool pavements Heat-pain ABSTRACT Global warming is intensifying the frequency and severity of heat waves, making urban environments increasingly hostile, especially during the summer months. Pavement surfaces are particularly vulnerable, often reaching extreme temperatures that cause significant thermal discomfort, contact burns and material degradation. This study presents an innovative solution based on nature: a cold pavement system that takes advantage of naturally cooled subsurface water to reduce surface temperatures by conduction, without relying on evaporation or water consumption due to the absence of capillarity. The system is particularly suitable for hot climates and outdoor public spaces where users can walk barefoot, such as coastal promenades or water parks. To evaluate its performance, a digital thermal model was developed and experimentally validated in real conditions in Seville, Spain, during the summer of 2023. A sensitivity analysis identified optimal design parameters, including pavement thickness, thermal conductivity, absorptivity and water heat exchange. Results indicate that this passive cooling strategy can reduce surface temperature by up to 20 ◦C compared to conventional pavements, while maintaining safe thermal conditions for more than 80 % of the exposure time and systematically avoiding harmful contact thresholds. This nature-based approach demonstrates great potential to improve outdoor urban thermal comfort, mitigate heat-related health risks, and support the development of more sustainable and climate-resilient urban environments. 1. Introduction 1.1. Context The intensification of climate change and its adverse effects are presenting increasingly complex challenges in urban environments, impacting both the well-being of residents and the environmental quality of cities Intergovernmental Panel on Climate Change [1]. Rising global temperatures, combined with extreme weather patterns, are worsening living conditions in urban areas, where the built environment significantly contributes to heat retention and overheating [2]. Urbanization has increased the use of heat-absorbing materials like asphalt and concrete, raising local temperatures and harming environmental quality [3]. These urban elements, prevalent in streets, squares, and other public spaces, exacerbate temperatures in surrounding areas and create unfavourable microenvironments that discourage outdoor activities and limit the thermal comfort of residents [4]. Furthermore, the reduction of green spaces and vegetation within urban environments diminishes the natural cooling capacity of cities [5,6]. This, coupled with a lack of shade and intense solar radiation, further complicates the habitability and enjoyment of public spaces [7]. Considering this issue, prioritizing the design and evaluation of mitigation strategies to regulate temperatures and alleviate the adverse effects of the built environment is essential. Incorporating sustainable solutions—such as low-heat absorption materials, expanded green spaces, and passive cooling infrastructure—helps mitigate climate change impacts while fostering cities better prepared for future challenges. In hot summer climates, high temperatures can turn concrete and asphalt floors into heat sources that pose a danger to anyone who walks on them. The combination of direct solar radiation and absorbed radiant heat causes certain surfaces in the urban environment, such as asphalt roads and concrete pavements, to reach temperatures significantly ☆ This article is part of a special issue entitled: ‘NBS for Climate Change’ published in Energy & Buildings. * Corresponding author. E-mail address: [email protected] (M. Carmen Guerrero Delgado). Contents lists available at ScienceDirect Energy & Buildings journal homepage: www.elsevier.com/locate/enb https://doi.org/10.1016/j.enbuild.2025.115945 Received 31 March 2025; Received in revised form 21 May 2025; Accepted 28 May 2025 Energy & Buildings 343 (2025) 115945 Available online 31 May 2025 0378-7788/© 2025 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/bync-nd/4.0/ ). higher than the surrounding air temperature [8]. Research, including studies by Harrington et al. [9] suggests that while burns can occur at a skin temperature of 44 ◦C, contact with surfaces can cause seconddegree burns within 35 s when air temperatures exceed 35 ◦C. With cities experiencing extremely hot summers, and daytime temperatures frequently surpassing 40 ◦C, the soil in these areas can become intensely hot, leading to discomfort and potential burns on the feet of barefoot guests. This situation is not only critical for city dwellers but also for various animal species, which can suffer burns on their feet when walking on these extremely hot pavements, particularly in areas that lack shelter from shadows. Burns from hot surfaces during the summer months are relatively common, particularly in hot desert climates. For instance, the study by M.M. Al-Qattan [10] highlights the burns suffered by Muslims on the day of the weekly mass. Before entering the mosque, Muslims leave their sandals outside, and after the service, these sandals may be misplaced or lost. Standing or walking barefoot in the street at that time of day can result in burned feet. The issue extends beyond the potential for burns to the inhabitants; it can also lead to fatal consequences. In June 2024, temperatures in Grand Mecca soared to 51.8 ◦C [11] leading to 550 pilgrim deaths during the Hajj, mostly due to heat stress. As a result, health officials reported nearly 5,800 cases of heat-related illnesses, underscoring the urgent need for interventions to combat heat stress. Additionally, the research conducted by Asquith et al. [12] emphasizes cases of burns on children’s bare feet while playing in public play areas. A study conducted by Saquib et al.[13] concluded that admissions to their health centre for burns in children began even when the outside air temperature was as low as 35 ◦C. Furthermore, the work of Shakirov et al. [14] indicates that even in Central Asian climates, burns from contact with concrete and asphalt surfaces account for up to 16.6 % of total burns in children, making it the second most common type of burn. 1.2. Cool pavements In response to urban thermal challenges, cool materials have emerged as an effective solution to mitigate urban overheating and address heat-pain issues. These materials are specifically designed to minimize heat absorption and reflect solar radiation, thereby reducing the surface temperature of paved areas and enhancing thermal comfort in urban environments [15]. Among the most advanced climate adaptation strategies, Nature-Based Solutions (NBS) play a significant role by offering green, blue, and grey solutions for heat mitigation [16]. Green solutions involve the implementation of green roofs and tree planting [17]; X. [18]), while blue solutions focus on incorporating water systems into urban design [19]. However, this study primarily emphasizes grey solutions, which include interventions in building and paving materials. In this context, cool floor coverings have gained interest. There are different types, such as reflective ones, which increase the surface’s ability to reflect heat; porous ones, which allow water to pass through and help cool the floor; and photovoltaic ones, which not only reduce the temperature, but also generate energy from sunlight [20]. Reflective pavements are engineered with high reflectivity and emissivity towards solar energy, aimed at reducing the absorption of solar radiation and enhancing the emission of infrared radiation [8,21]. This is accomplished by minimizing radiation absorption within the concrete structure, which leads to a decrease in surface temperature and heat retention. While this technology has been widely researched and is relatively straightforward to implement, significant installation and maintenance costs present challenges, along with issues related to the thermal and visual comfort of urban residents [22,23]. On the other hand, permeable and water-retentive pavements possess a greater number of voids compared to conventional pavements, allowing water to permeate into the sub-layers and the ground below [24,25]. These pavements can retain absorbed water and utilize it for cooling through evaporation, thereby lowering their surface temperature. Additionally, it is suggested that the filtering capabilities of permeable pavements may aid in enhancing groundwater quality [26,27]. However, a primary disadvantage of this pavement type is the water consumption associated with evaporation as a cooling mechanism. There are various experimental proofs of concept for these cold pavement technologies. For instance, Ruas et al. [28] conducted a study comparing various technologies like reflective paving, evaporative paving, and different shading qualities for outdoor paving in Paris, France. While this study assesses comfort indicators based on UTCI, it does not address the visual discomfort associated with reflective pavements. Other significant studies on reflective pavements include those conducted by Middel et al. [29] and Kousis et al. [30]. The former investigates the thermal behaviour of asphalt pavements concerning their reflective layers, while the latter examines a type of pavement that utilizes phosphorescence to assess its hygro-thermal and radiative properties. Several studies have been conducted on evaporative pavement technology. One notable study by Wang et al. [24] explores the impact of evaporative cooling from two types of permeable flooring on outdoor thermal comfort in Guangzhou (China). While this research yields insightful results, the specifics of technological implementation remain ambiguous. Another study conducted by Liu et al. [31] investigates the thermal comfort of the human body when porous flooring is wetted in Lanzhou (China). The findings indicate that outdoor thermal comfort diminishes when outdoor temperatures exceed 20 ◦C and relative humidity increases. Despite advancements in the development of these materials and recent contributions to the field, the scientific literature remains limited regarding innovative pavement designs aimed at effectively reducing surface temperatures and comprehensively mitigating heat effects in urban spaces. This limitation represents a significant gap for future research in the pursuit of more resilient cities. For this reason, the authors of this paper proposed an innovative cold screed solution in a previous article [32]. The objective of this technology is to cool pavements using naturally cooled water, thereby evaluating its potential to reduce its surface temperature without depending on the evaporative cooling effects of traditional evaporative pavements and the associated water usage. This approach consists of allowing cold water to flow under the bottom surface of the pavement without capillary action, which cools the bottom surface when it meets Nomenclature Abbreviations LMTD Log mean temperature difference NBS Nature-based solution PUR Polyurethane foam Symbols ∝Thermal diffusivity [m 2 /s] c p Specific heat capacity [J/kg K] k Thermal conductivity [W/m K] ρ Density [kg/m 3 ] t Time [s] T A,0 Maximum allowable material temperature [◦C] T air Outdoor temperature [◦C] T B,0 Initial skin temperature [◦C] T overheating Overheating temperature [◦C] T pavement Upper surface pavement temperature [◦C] T PM Contact temperature [◦C] T skin Temperature at the interface [◦C] X Contact conductance [W/m 2 K] P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 2 the water. Consequently, there is a reduction in the temperature of the upper surface due to conduction and the sensible heat of the water. As a result, the pavement has an inherently low water consumption during the cooling process. This innovative technological approach not only contributes to the renaturation of cities and alleviates urban overheating, but also addresses the problems related to contact burns caused by extreme surface temperatures. However, the adoption of this innovative solution by the scientific community will depend on research that defines its optimal operating conditions, assessing durability, economic feasibility, environmental impact, and efficiency through real case studies. Furthermore, largescale pilot studies and comparative analyses with existing technologies will be essential to validate its effectiveness and promote implementation. 1.3. Objectives The main objective of this study is to evaluate an innovative cold pavement solution aimed at reducing burn risks in real-world settings, particularly in public areas where barefoot walking is common, such as water parks or coastal paths in hot climates. Given that summer temperatures in these regions often exceed 40 ◦C, surface heat poses a health and safety risk. This study explores a cold pavement concept to lower surface temperatures and enhance visitor safety, focusing on the following key aspects: •Analysis of the effects of high temperatures on conventional sunexposed pavements, focusing on barefoot burn risks and safety implications. •Design of a cold pavement concept with improved thermal performance, identifying properties that reduce heat absorption. •Development of a digital model to simulate and compare the thermal behaviour of the cold pavement versus conventional surfaces. •Sensitivity analysis to determine the optimal pavement configuration based on material performance. •Technological implementation in a 100 m 2 pilot to analyse technical aspects and economic factors. 2. Methodology In this study, a model is proposed to predict the thermal performance of innovative cold pavements, based on experimental testing and subsequent validation. A proof of concept was conducted during the summer of 2023 to evaluate a passive cooling solution using naturally cooling materials [32]. The promising results led to a case study exploring these pavements as a solution for contact burns and discomfort caused by overheated surfaces. Based on these findings, a mathematical model was developed to simulate pavement performance under various climatic conditions. The concept of contact temperature is central to assessing the safety and effectiveness of cold pavements. To estimate it, the material’s thermal properties are analysed, including its capacity to absorb and dissipate heat in diverse environmental contexts. Based on these principles, a simplified design model is created to predict thermal behaviour across different climates. Experimental results are integrated to calibrate the model and enhance prediction accuracy. The model aims to estimate both surface and contact temperatures in specific scenarios, assessing the pavement’s potential to mitigate adverse thermal effects in urban and recreational settings. For validation, a case study is implemented in a real-world waterpark environment with extreme temperatures. Simulated values are compared with on-site measurements to verify the model’s accuracy in predicting pavement temperature and evaluating its contribution to Fig. 1. Methodological outline of the process. P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 3 thermal safety. Additionally, a sensitivity analysis is performed to assess different combinations of design variables such as material type, colour, texture, and conductivity. Fig. 1 outlines the whole process. 2.1. One-dimensional transient conduction modelling 2.1.1. Theoretical mathematical modelling In this section, the mathematical model used as a ’’Digital Twin’’ of the thermal behaviour of pavements is presented. The numerical model is employed to evaluate the effectiveness of the proposed conceptual solution under the Dubai climate conditions. To investigate the performance of opaque elements under varying boundary conditions, the analysis commences with the fundamental equation of heat conduction with generation, as outlined in Eq. (1). ∂ ∂ x(k ∂ T ∂ x)+ ∂ ∂ y(k ∂ T ∂ y)+ ∂ ∂ z(k ∂ T ∂ z)+G= ρ C ∂ T ∂ t(1) Particularizing this expression for the unidirectional case without generation, the resulting expression is shown in Eq. (2). ∂ ∂ x(k ∂ T ∂ x)= ρ C ∂ T ∂ t(2) The equation is determined by the boundary conditions that describe the pavement scenario. The boundary condition on the upper surface pertains to the energy equilibrium at that specific surface. The main factors contributing to this are the absorption of short-wavelength radiation (from the sun), long-wavelength radiant transfer between the pavement surface and the sky, and convective transfer resulting from the pavement surface’s interaction with the ambient air. In the reference (conventional) situation, the bottom surface will have a temperature imposed by the temperature variation of the ground as a function of depth and observation period. Conversely, for a wet pavement scenario, the temperature at this surface corresponds to that of the circulating water. To solve Eq. (2), numerical modelling is established, discretizing the domain with a sufficiently small mesh so that uniform temperature can be assumed in each cell. For each pavement node, Fig. 2 proposes an incremental balance as follows by Eq. (3). ρ CpΔxi( ∂ Ti ∂ t)=(Ti+1−Ti Ri+Ti−1−Ti Ri−1)(3) When solving the derivative term concerning time, two potential discretization methods can be employed: either explicitly Eq. (4) or implicitly Eq. (5). ρ CpΔxi(Ti,j−Ti,j−1 Δt)=(Ti+1,j−1−Ti,j−1 Ri+Ti−1,j−1−Ti,j−1 Ri−1)(4) ρ CpΔxi(Ti,j−Ti,j−1 Δt)=(Ti+1,j−Ti,j Ri+Ti−1,j−Ti,j Ri−1)(5) In this case, the implicit method will be used as it is more complex but will provide more reliable and stable results. The resulting matrix equation for the implicit method is presented in Eq. (6), detailing its components in Eqs. (7)–(9). [MA]⋅[T] = [VB](6) Fig. 2. Energy balance in node. [MA] = ⎛ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎝ 1+ ρ eceΔx2 2keΔt−1 −k(i)Ci ρ iΔx2+(ki+1+ki)Δt Δt 0 0 −k(i+1)0 ⋯0 ⋯0 0−k(i) 0 0 Ci ρ iΔx2+(ki+1+ki)Δt Δt−k(i+1) −k(i)⋱ ⋯0 ⋯−k(i+1) ⋮ ⋮ 0 0 ⋮0 0 0 −k(i)Ci ρ iΔx2+(ki+1+ki)Δt Δt ⋯−1 0 0 ⋮ 0 −k(i+1) 1+ ρ eceΔx2 2keΔt+hiΔx ki ⎞ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎠(7) P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 4 T= ⎛ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎝ Ti,j Ti+1,j Ti+2,j Ti+3,j ⋮ Tn,j ⎞ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎠ (8) [VB] = ⎛ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎝ Text heΔx ke+Ti,j−1 ρ eCeΔx2 2keΔt ⋮ Ti,j−1 ρ iCiΔx2 Δt ⋮ Tinr hiΔx ki+Ti,j−1 ρ iCiΔx2 2kiΔt ⎞ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎠ (9) In this context, the unknowns represent the temperatures at individual nodes for each time step, with the surface temperature of the pavement serving as the evaluation variable. 2.1.2. Experimental evaluation The parameters of the proposed model are obtained from experiments conducted by the authors. Recognition within the scientific community is established through theoretical contribution[33,34]. This section summarizes the data obtained from an experimental evaluation of the concept under study. The proof of concept represents the initial phase of the authors’ investigation into this innovative cool pavement solution[32]. Fig. 3 presents the prototype of the experimental facility being studied. This experimental facility consists of three key systems designed to test the thermal behaviour of the cool pavements: Water pond (Cold-water supply source): The water pond serves as the main reservoir to supply cold water throughout the experiment. It functions as a thermal buffer, keeping the water temperature stable to ensure consistent experimental conditions. The water stored in this pond is used to simulate realistic cooling scenarios, facilitating the controlled flow of water through the hydraulic system and underneath the pavement samples. The thermal properties of the pond, such as heat absorption and dissipation rates, are crucial to evaluate the overall effectiveness of the cooling system. Water supply system (Controlled water distribution): The hydraulic system is responsible for the controlled supply of water to the paving station. This system includes a network of pipes, valves and pumps that regulate water flow, pressure and distribution. It ensures a constant and uniform supply of water under the pavement surfaces, allowing precise control of the cooling effects. The system is designed Fig. 3. Experimental cool pavement prototype [32]. Fig. 4. Experimental thermal performance of the cool pavement solution. P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 5 to simulate real-world conditions where water is used as a cooling mechanism in urban pavement environments. Pavement Station: This is the core of the experimental setup, where the thermal performance of pavement samples is analysed under controlled conditions. This station is specifically designed to facilitate a systematic comparison between dry and wet pavement scenarios. In the dry pavement station, pavement samples are exposed to environmental conditions without any water interaction. The objective is to study their natural thermal response to solar radiation, air temperature, and other climatic factors. Temperature sensors embedded in the pavement measure surface and subsurface temperature variations over time. This analysis establishes a baseline for understanding how conventional dry pavements retain and dissipate heat. The second section of the paving station examines the impact of water flow under the pavement surface. A controlled volume of water is circulated beneath the pavement layers to assess its cooling potential. By monitoring temperature fluctuations in real time, researchers can quantify how effectively the water circulation mitigates heat buildup. This analysis is essential to determine the feasibility of implementing water-based cooling strategies in urban infrastructure. To ensure the reliability of the results, two identical pavement samples are tested simultaneously: one dry and one with water circulation underneath. Since both samples are subjected to identical environmental conditions, any temperature variations observed between them can be directly attributed to the cooling mechanism being tested. This controlled approach eliminates extraneous variables, ensuring that the results accurately reflect the potential benefits of the proposed cooling pavement concept. Climate data are recorded by means of a climate station located in situ in the experimental facility, as well as a backup station located at the School of Engineering of the University of Seville during the summer of 2023. On the other hand, Fig. 4 presents the temperature curves of the dry upper surface of the pavements, which serve as a reference, alongside the cool pavement under evaluation, ambient air temperature, and the temperature of the water used for natural cooling. The wet experiments begin at 14:00, during which water circulates beneath the bottom surface of the pavement. This water flow, occurring from 14:00 to 18:00, is designated as the ’On Period,’ depicted in the graph by the light blue area. This timeframe coincides with peak solar radiation hours, during which pedestrian traffic decreases as individuals seek shelter indoors, thereby enhancing comfort during extreme conditions. Subsequently, the ’Off Period’ commences, which is analysed to evaluate the thermal response resulting from the wetting during the ’On Period.’ This phase is vital as it marks the onset of increased pedestrian activity in public spaces, emphasizing the importance of thermal comfort. It is noted that both dry and wet pavements exhibit a gradual and remarkably similar temperature trajectory until 14:00 when water circulation begins. The cool pavement quickly reacts to the cooling effect of the water, leading to a significant decrease in the temperature of the pavement’s upper surface compared to the dry reference. This temperature reduction is substantial enough for the pavement to lower its temperature below that of the outdoor air. Moreover, after the cessation of water circulation, the wet pavements continue to maintain a temperature that remains lower than the outdoor air temperature, while the dry pavements stay warmer until nighttime. 2.1.3. Theoretical model validation To validate the model, results from a pavement survey conducted in summer 2023 are compared with the numerical outputs of the computational model described in Section 2.1.1. Specifically, 85 % of the experimental data from the 2023 campaign are used for comparison. The results show strong alignment between the simulated and experimental values, both in trend and magnitude. Fig. 5 illustrates this agreement with a scatter plot, where each point represents a pair of experimental and simulated temperatures recorded simultaneously. The points closely follow the bisector, indicating a near one-to-one match. The model’s accuracy is further supported by an error margin of less than 5 % for most data points, confirming its reliability. 2.2. Practical application Beyond validating individual models, it is crucial to establish connections between modelled elements to accurately predict cold pavement behaviour. The developed model serves as a link between controlled experiments and real-world applications, enabling the analysis of variables such as material type, colour, thermal properties, and the effect of groundwater circulation. This approach allows laboratory results to be extrapolated to real urban settings. To support this, a case study is defined in which a cold pavement prototype is designed and implemented. 2.2.1. Extreme heat challenges in urban public spaces In extremely hot climates, urban public spaces like water parks and coastal walkways face significant challenges due to elevated pavement temperatures. For instance, water parks are designed to offer visitors a refreshing escape from high temperatures, but in arid and extremely hot regions, environmental conditions create unexpected problems. One of the most pressing problems faced by visitors is excessive heating of the pavements surrounding the pools. Due to prolonged exposure to intense solar radiation and constant high temperatures throughout most of the year, these surfaces reach dangerously high temperatures, posing a significant risk to barefoot visitors. Such climate conditions are characterized by prolonged periods of intense heat, with summer temperatures often exceeding 40 ◦C and extreme solar radiation that significantly increases surface temperatures. The combination of low humidity, high air temperatures, and strong sunlight results in rapid heat absorption by materials such as pavement and concrete, making outdoor surfaces particularly hazardous for direct human contact. A frequent consequence of this extreme heat is contact burns on the soles of visitors’ feet when they walk on these overheated pavements after leaving the pools. This problem not only causes discomfort, but also represents a serious safety hazard, which can negatively impact the Fig. 5. Experimental validation of the numerical model. P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 6 Fig. 6. Proposed application for channel formation. P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 7 overall visitor experience. If left unaddressed, this problem could reduce the attractiveness of the park as a recreational destination, ultimately affecting visitor satisfaction and attendance. 2.2.2. Description of the design Water management in cold pavements is a key factor for thermal regulation and optimization of water resources. To mitigate this problem, this study explores an innovative cold pavement solution designed to reduce surface temperatures through an integrated cooling system without evaporative losses of water. For this purpose, corrugated galvanized steel sheets and a PVC pipe system are used. Fig. 6 details the assembly process, from fabrication to installation, ensuring the hydraulic functionality and structural strength of the system. The system is composed of various structural and functional elements that allow its correct performance. 1. Previous concrete slab: Acts as a structural base and support point for the channels. This slab provides mechanical stability and minimizes the need for additional structures for the installation of the system. 2. Mass concrete: 10 cm thick top layer that protects the system and distributes the loads. The circulation of cold water inside the channels generates a conductive heat flow in which the cement provides thermal stability. 3. Corrugated galvanized steel sheet: 0.5 mm thick metal sheet that forms the water channels. Its corrugated design allows the formation of trapezoidal sections of 0.0824 m 2 generating an efficient water storage and conduction system. A 1 m wide corrugated sheet produces 4 water channels. The corrugated sheets are arranged by distinguishing between the central sheets and the end sheets. Given that there are 4 trapezoids per sheet, the area per sheet is 0.03296 m 2 . Consequently, a standard 12 m sheet can hold 0.39552 m 3 of water, resulting in a total of 3.296 m 3 of water for 100 m 2 of cold pavement. 4. Polyurethane foam sealing: Used as a seal between PVC pipes and steel sheets, preventing leakage and ensuring structural stability. 5. PVC pipe: This 32 mm diameter pipe is responsible for transporting the accumulated water to the galvanized steel sheets, as well as to the drainage or reuse system. The implementation of the system follows a two-phase methodology. Phase 1 focuses on the fabrication of the channel end pieces in the workshop, allowing the manufacturing conditions to be controlled. This requires the cutting and subsequent bending of a 2 mm thick plate in dimensions of 150 mm and 350 mm to serve as a structural base. The galvanized steel sheet (3) is installed on this base, ensuring that it adopts the required shape in the channels. Epoxy resin and self-drilling screws are used to join the 32 mm diameter pipe (5) with the sheet and the base created. Finally, polyurethane foam (5) is used between the corrugated sheet (2) and the PVC pipe (4) to prevent leaks and provide airtight joints. Phase 2 allows the installation of the system in the building by laying the corrugated sheets created during phase 1 on the existing concrete slab (1). It is essential to assemble these pieces with the supply and drainage networks, as well as to ensure the fit and sealing of the connections with polyurethane foam reinforcements if necessary. Finally, a 10 cm thick layer of cement overlay is poured over the channels, ensuring uniform load distribution and integration with the existing infrastructure. To optimize the hydraulic efficiency of the system, the design of the piping network follows a staggered configuration that allows the correct evacuation of the water. The conduction system is composed of a 100 mm diameter pipe, which functions as the main conduit of the system. It consists of a 100–40 mm T-joint that allows the bifurcation of the water flow into smaller sections, redirecting the flow in a more controlled manner and minimizing pressure loss thanks to two 45◦elbows. Finally, a 40–32 mm reducer allows the water to be conveyed to the final 32 mm pipe, taking care of the discharge or reuse of the water in the system. 2.2.3. Simulation conditions The calculation tool is TRNSYS 18 [35], which is used by other authors to analyse the performance of cold pavement and other technologies based on natural techniques [34]. This program is essential to analyze the energy system of the solution applied to the water park, considered a system that stores and generates energy. The modeled system consists of these three elements: •Cold pavements: The cold pavement acts as a heat exchanger, where cold water circulates through internal channels, reducing the surface temperature. •Water storage tank: A tank is incorporated where the previously cooled water is stored. This tank is essential for the continuous supply of water to the channels and the thermal regulation of the pavement. It is modelled in TRNSYS with Type 39, ensuring efficient control of temperature and water flow. •Water cooling system: Two cooling systems are used to reduce the water temperature. First, a passive cooling system using a falling film is considered, since the buildings and surroundings located in the water park have enough space for photovoltaic panels [36–38]. This mechanism allows the heat accumulated in the water to dissipate at night, ensuring that the system is ready to operate efficiently during the day [36]. In both cases, the simplified models published by the authors are implemented as a function using the TRNSYS editor. The cold screed operates dynamically, adjusting its operation according to the ambient temperature and the temperature of the stored water. Nighttime water cooling operates for 8 h. Meanwhile, evaporative misting cooling is implemented for 12 daytime hours. The chilled water circulates through the pavement channels when the air temperature exceeds 30 ◦C and the tank temperature is below 27 ◦C. The groundwater storage volume is estimated at 70 m 3 to ensure sufficient cooling for at least 6 h. On the other hand, the nighttime dissipation area of the falling sheet technology is considered equal to 380 m 2 . The months from May to October are tested because they are considered the most critical in Dubai due to the high temperatures and incident solar radiation on the pavements. An ENVI-met model [39] is used to calculate the ambient and surface temperatures reached in these months, as well as to determine the incident solar radiation. This input data is included in TRNSYS, using a TMY (Typical Meteorological Year) file to perform the simulations. 2.2.4. Pavement thermal evaluation A detailed thermal study will be carried out on the conventional pavement exposed to various climatic conditions, with the objective of characterizing its thermal behaviour during the hottest month in Dubai. The pavement surface temperature profile and the degree of overheating in relation to the ambient temperature will be analysed. This reference scenario will serve as a point of comparison to quantify the improvements obtained through the implementation of cold pavement technology. The circulation areas of the water park in the reference situation are composed of different layers of material, whose thermal properties are detailed in Table 1. The absorptivity values considered are 0.4 for lightcoloured surfaces and 0.55 for medium-coloured surfaces. These values are derived from the absorptivity measurements of the pavement Table 1 Reference pavement material layers. Materials Thickness (m) Conductivity (W/ mK) Density (Kg/m 3 ) Specific Heat (J/KgK) Concrete slab 0.1 1.6 2100 1179 Gravel 0.45 1.4 2000 880 Soil 1.45 1.25 2425 890 P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 8 samples evaluated during a previous experimental campaign conducted in Seville [32], which is summarized in Table 2. The values of 0.4 and 0.55 represent the averages of all the light-coloured and mediumcoloured samples, respectively. To analyse the performance of different cold pavement solutions, simulations have been carried out considering different design variables. The thermal properties of the material such as conductivity, density and specific heat are considered, as well as the thickness of the tested pavement, its surface absorptivity and the temperature of the water used in the cooling system. The thermal properties of the materials considered in the analysis are presented in Table 3, where four different types of cement are grouped with variations in their conductivity, density and heat capacity. To evaluate the influence of each of these properties on the thermal behaviour of the pavement, simulations have been carried out keeping all other variables constant while modifying the parameter of interest. This analysis allows us to quantify and compare the impact of each property on the pavement surface temperature. 2.3. Pavement touch temperature 2.3.1. Modelling and calculation of contact temperature Defining temperature limits for skin contact with both hot and cold objects is crucial to prevent pain and skin damage. Three different methods can be used to estimate this parameter. The first is a simplified time-independent approach, assuming perfect thermal contact. The second corresponds to a detailed time-dependent approach, considering the transient effects of conduction. Finally, there is an experimental approach, based on empirical data to validate the detailed model. The contact temperature (T A ) can be determined by using the transient conduction solution in semi-infinite solids. This contact temperature occurs at the dermal/epidermal interface, approximately 0.25 mm below the surface. A simplified and conservative solution involves considering the contact temperature directly at the surface and assuming infinite thermal conductivity of the contact material (perfect contact between skin and material). This time-independent solution is represented by Eq. (10). Tskin =((k ρ Cp) 1 2 ATA,0+(k ρ Cp) 1 2 BTB,0 (k ρ Cp) 1 2 A+(k ρ Cp) 1 2 B )(10) where T B,0 is the initial skin temperature, T skin is the temperature at the interface, and T A,0 is the maximum allowable material temperature that ensures that the skin temperature limits are not exceeded. k, ρ ,Cp are the conductivity, density and specific heat of the material. In the assessment of validating the contact temperature using the provided equation, an example of contact temperature is compared with a detailed procedure outlined by Eugene Ungar (Stroud, n.d.). The detailed procedure is presented in Eq. (11). TPM =[Tskin(0)+Tobject(0)]• kobject  α object √ kobject  α object √+kskin  α object √ •{erfc(|X| 2 α object •t √)−exp(h2|X|+h2 2 α skint) •erfc(|X| 2 α object •t √+h2 α objectt √)} (11) It has been observed that using the following parameters in the detailed model results in an excellent correlation with previously conducted tests: an initial skin temperature of 32.5 ◦C, a skin thermal conductivity of 0.54 W/m⋅K, a skin thermal diffusivity of 1.3 ×10 −7 m 2 /s, a contact conductance of 1000 W/m 2 ⋅K, a pain threshold of 44 ◦C at the dermal/ epidermal interface, and a dermal/epidermal interface located 0.25 mm below the surface. For the detailed model, a correlation from a NASA report [40] for an Table 2 Absorptivity of tested pavement samples. Colour Manufacturer 1 Manufacturer 2 Manufacturer 3 Manufacturer 4 Manufacturer 5 Mean Dark 0.69 0.71 0.67 0.60 0.64 0.67 Medium 0.64 0.53 0.51 0.42 0.46 0.55 Light 0.50 0.39 0.47 0.39 0.41 0.4 Table 3 Thermal properties provided for the paving material. Conductivity [W/m K] Density [kg/m3] Specific heat [J/kg K] Concrete 1 1.4 1800 940 Concrete 2 1.5 2000 900 Concrete 3 1.6 2100 850 Concrete 4 1.7 2250 800 Fig. 7. Touch temperature comparison (detailed method vs simplified method). Table 4 Results of the application of the detailed model. Detailed model time(s) a b T PM 1 15,500 55.2 61.79 10 15,500 46.4 52.99 30 15,500 44.8 51.39 60 15,500 44.3 50.89 Infinite 15,500 43.4 49.99 P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 9 using the sky temperature [36,38]. The percentage of coverage for nighttime dissipation is approximately 18 % and 13 %, depending on the water temperature. 4.3. Limitations and outlook Despite the encouraging results, several factors could limit real‑world performance. First, boundary‑condition variability may arise because the analysis assumes steady inlet‑water temperature and flow. In practice, diurnal stratification or fluctuating bather loads could lessen cooling effectiveness during peak occupancy. Then, long‑term durability must be addressed: prolonged exposure to chlorinated water, ultraviolet radiation and mechanical wear may degrade both the corrugated liner and the concrete, requiring accelerated ageing tests and bespoke maintenance protocols. Next, hydraulic fouling deserves attention. Biofilm formation inside warm channels can increase pressure drop and depress heat‑transfer rates, so periodic flushing or biocide‑dosing strategies should be devised. Later, spatial and energy constraints become relevant. Although longer channels reduce volumetric flow and pump size, they demand additional footprint and circuit complexity; moreover, pump electricity could offset part of the thermal benefit if it is not supplied from renewable sources. Finally, economic uncertainty remains. Labour and installation costs can vary widely across markets and should be incorporated into future life‑cycle assessments. Addressing the limitations above will require coordinated research spanning laboratory, field and socio‑economic studies. Priority lines of enquiry begin deploying prototype slabs under dynamic, real-life climate and operational conditions, including extreme heat waves and varying user loads, as well as in other climate zones, apart from hyper‑arid (Dubai) ones, such as Mediterranean (Athens or Seville) and humid‑subtropical (Houston or Singapore) sites to verify performance and durability under contrasting meteorological and water‑quality regimes and assess the scalability and robustness of the system design. In addition, adaptive hydraulic control can combine surface‑temperature sensors with predictive algorithms to modulate flow rate and minimise pump energy without compromising thermal safety. Furthermore, additional research into alternative materials with higher thermal conductivity or durability could further improve system performance. Material optimisation should investigate high‑conductivity, low‑carbon concrete mixes (e.g., basalt‑fibre‑reinforced geopolymers) and protective coatings to extend service life in chlorinated or saline environments. On the other hand, a comprehensive life‑cycle assessment (LCA) should quantify embodied energy, greenhouse‑gas mitigation and water savings relative to reflective and evaporative pavements, including sensitivity to regional electricity mixes. Subsequently, renewable‑energy integration must evaluate the techno‑economic feasibility of powering pumps and auxiliary equipment with rooftop photovoltaics or waste‑heat‑driven absorption chillers. Finally, user acceptance and usability studies will monitor perceived comfort, slip resistance and maintenance demands in operational settings to refine design guidelines and support regulatory approval. 5. Conclusion This study assessed the feasibility of an innovative, nature-based cold pavement solution designed to mitigate the thermal impact on urban surfaces, with a particular focus on preventing contact burns in extreme hot public spaces, such as water parks and coastal walkways in extremely hot climates. The findings confirm the effectiveness of this Fig. 14. Inverted return strategy. P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 16 technology in significantly reducing pavement surface temperatures, achieving a reduction of more than 19 ◦C compared to conventional pavements. A comprehensive analysis demonstrated that this solution not only minimizes the risk of burns but also enhances thermal comfort for users, particularly during peak solar exposure hours. The digital model, validated through experimental testing, confirmed that the cool pavement maintains acceptable temperature levels for over 80 % of the analysed hours, consistently remaining below critical thermal risk thresholds. The sensitivity analysis of key parameters, including absorptivity, thermal properties, and pavement thickness, enabled the identification of optimal configurations that maximize cooling performance and minimize surface temperature. Additionally, a preliminary economic evaluation suggests that this technology represents a viable and costeffective alternative to conventional solutions, with implementation costs significantly reduced under specific configurations. From a sustainability perspective, the efficient use of water resources and the potential integration of night-time radiative cooling strategies reinforce the viability of this solution as a climate-resilient measure for urban environments. However, while these results are promising, future research should focus on assessing the long-term durability and performance of this system across different climatic conditions to ensure scalability and adaptability. In summary, the cool pavement technology presented in this study offers a substantial contribution to mitigating urban overheating while promoting safer and more liveable cities. This innovative approach effectively addresses the risks associated with excessively heated surfaces, enhancing safety, thermal comfort, and the overall user experience in public spaces exposed to extreme temperatures. CRediT authorship contribution statement Paulo García-Melgar: Writing – original draft, Investigation, Data curation. Paz Montero-Guti´ errez: Writing – original draft, Investigation, Formal analysis, Data curation. María del Carmen Guerrero Delgado: Investigation, Methodology, Validation, Supervision. Alberto Cerezo Narv´ aez: Visualization, Investigation, Conceptualization. Jos´ e S´ anchez Ramos: Validation, Project administration, Methodology, Investigation, Funding acquisition. Servando ´ Alvarez Domínguez: Methodology, Investigation, Conceptualization. Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgements This study has been funded by the projects “CONSTANCY - Resilient urbanisation methodologies and natural conditioning using imaginative nature-based solutions and cultural heritage to recover the street life” (Grant Agreement PID2020-118972RB-I00) and the project “COSMIC - Combined AI and Data Solutions for Large Scale Resource Optimization with Green Deal Impact” (Grant Agreement GA-101189676) by the European Commission. The second author is supported by the Spanish Ministry of Science, Innovation and Universities through a PhD grant agreement FPU22/03587. Data availability Data will be made available on request. References [1] Intergovernmental Panel on Climate Change (IPCC). (2023). Climate Change 2022 – Impacts, Adaptation and Vulnerability. Cambridge University Press. https://doi. org/10.1017/9781009325844. [2] Santamouris, M. (2020). Recent progress on urban overheating and heat island research. Integrated assessment of the energy, environmental, vulnerability and health impact. Synergies with the global climate change. In Energy and Buildings (Vol. 207). Elsevier Ltd. https://doi.org/10.1016/j.enbuild.2019.109482. [3] A.M.M. Irfeey, H.W. Chau, M.M.F. Sumaiya, C.Y. Wai, N. Muttil, E. Jamei, Sustainable Mitigation Strategies for Urban Heat Island Effects in Urban Areas, Sustainability (switzerland) 15 (14) (2023), https://doi.org/10.3390/ su151410767. [4] Mandi´ c, L., Đjuki´ c, A., Mari´ c, J., & Mitrovi´ c, B. (2024). A Systematic Review of Outdoor Thermal Comfort Studies for the Urban (Re)Design of City Squares. In Sustainability (Switzerland) (Vol. 16, Issue 12). Multidisciplinary Digital Publishing Institute (MDPI). https://doi.org/10.3390/su16124920. [5] M. Baradaran Motie, M. Yeganeh, M. Bemanian, Assessment of greenery in urban canyons to enhance thermal comfort & air quality in an integrated seasonal model, Appl. Geogr. 151 (2023) 102861. https://doi.org/10.1016/j.apgeog.2022.102861. [6] F. Marando, M.P. Heris, G. Zulian, A. Udías, L. Mentaschi, N. Chrysoulakis, D. Parastatidis, J. Maes, Urban heat island mitigation by green infrastructure in European Functional Urban Areas, Sustain. Cities Soc. 77 (2022) 103564, https:// doi.org/10.1016/j.scs.2021.103564. [7] Lic´ on-Portillo, J. A., Martínez-Torres, K. E., Chung-Alonso, P., & Herrera Peraza, E. F. (2024). From Block to City Scale: Greenery’s Contribution to Cooling the Urban Environment. In Urban Science (Vol. 8, Issue 2). Multidisciplinary Digital Publishing Institute (MDPI). https://doi.org/10.3390/urbansci8020041. [8] M. Santamouris, Using cool pavements as a mitigation strategy to fight urban heat island - A review of the actual developments. In, Renew. Sustain. Energy Rev. 26 (2013) 224–240, https://doi.org/10.1016/j.rser.2013.05.047. [9] Harrington, W. Z., Strohschein, B. L., Reedy, D., Harrington, J. E., & Schiller, W. R. (1995). Pavement Temperature and Burns: Streets of Fire. [10] M.M. Al-Qattan, The “Friday Mass” burns of the feet in Saudi Arabia, Burns 26 (1) (2000) 102–105, https://doi.org/10.1016/S0305-4179(99)00097-2. [11] Le Monde. (2024, June 19). Mecca: More than 550 pilgrims died in sweltering heat during Hajj. https://www.lemonde.fr/en/international/article/2024/06/19/mo re-than-550-pilgrims-die-during-hajj-many-from-extreme-heat_6675120_4.html. [12] C. Asquith, R. Kimble, K. Stockton, Too hot to trot (barefoot)… A study of burns in children caused by sun heated surfaces in Queensland, Australia, Burns 41 (1) (2015) 177–180, https://doi.org/10.1016/j.burns.2014.06.011. [13] Saquib FACS, S., Carroll, J., Flores, C., Chestovich FACS, P., & Saquib, S. F. (2021). Management of Pediatric Pavement Burns. https://doi.org/10.1093/jbcr/irab084/ 6279081. [14] B.M. Shakirov, B.S. Tursunov, Treatment of severe foot burns in children, Burns 31 (7) (2005) 901–905, https://doi.org/10.1016/j.burns.2005.04.022. [15] A. Synnefa, A. Dandou, M. Santamouris, M. Tombrou, N. Soulakellis, On the use of cool materials as a heat island mitigation strategy, J. Appl. Meteorol. Climatol. 47 (11) (2008) 2846–2856, https://doi.org/10.1175/2008JAMC1830.1. [16] Leroy, A. (2021). Urban cooling solutions Drawing inspiration from worldwide case studies to address variability in current and future climates. www.carrenoir. com. [17] G.L. Feyisa, K. Dons, H. Meilby, Efficiency of parks in mitigating urban heat island effect: an example from Addis Ababa, Landsc. Urban Plan. 123 (2014) 87–95, https://doi.org/10.1016/j.landurbplan.2013.12.008. [18] X. Wang, M. Dallimer, C.E. Scott, W. Shi, J. Gao, Tree species richness and diversity predicts the magnitude of urban heat island mitigation effects of greenspaces, Sci. Total Environ. 770 (2021), https://doi.org/10.1016/j.scitotenv.2021.145211. [19] Y. Lin, Z. Wang, C.Y. Jim, J. Li, J. Deng, J. Liu, Water as an urban heat sink: Blue infrastructure alleviates urban heat island effect in mega-city agglomeration, J. Clean. Prod. 262 (2020), https://doi.org/10.1016/j.jclepro.2020.121411. [20] Li, S., Ma, T., & Wang, D. (2023). Photovoltaic pavement and solar road: A review and perspectives. In Sustainable Energy Technologies and Assessments (Vol. 55). Elsevier Ltd. https://doi.org/10.1016/j.seta.2022.102933. [21] H. Akbari, L.S. Rose, Urban surfaces and heat island mitigation potentials, J. Hum. Environ. Syst. 11 (2008) 85–101. [22] A. Sha, Z. Liu, K. Tang, P. Li, Solar heating reflective coating layer (SHRCL) to cool the asphalt pavement surface, Constr. Build. Mater. 139 (2017) 355–364, https:// doi.org/10.1016/j.conbuildmat.2017.02.087. [23] N. Xie, H. Li, H. Zhang, X. Zhang, M. Jia, Effects of accelerated weathering on the optical characteristics of reflective coatings for cool pavement, Sol. Energy Mater. Sol. Cells 215 (2020), https://doi.org/10.1016/j.solmat.2020.110698. [24] J. Wang, Q. Meng, K. Tan, M. Santamouris, Evaporative cooling performance estimation of pervious pavement based on evaporation resistance, Build. Environ. 217 (2022), https://doi.org/10.1016/j.buildenv.2022.109083. [25] Y. Wardeh, E. Kinab, G. Escadeillas, P. Rahme, S. Ginestet, Review of the optimization techniques for cool pavements solutions to mitigate Urban Heat Islands, in: Building and Environment, Vol. 223, Elsevier Ltd., 2022, https://doi. org/10.1016/j.buildenv.2022.109482. [26] A. Berland, S.A. Shiflett, W.D. Shuster, A.S. Garmestani, H.C. Goddard, D. L. Herrmann, M.E. Hopton, The role of trees in urban stormwater management, Landsc. Urban Plan. 162 (2017) 167–177, https://doi.org/10.1016/J. LANDURBPLAN.2017.02.017. [27] Hawxwell, T., Suska, P., Padilla, M., Mok, S., Schaufler, C., Pegg, I., Uhlenbruch, M., Libov´ a, T., Gargori Reverter, L., Onzon, T., Onur, ¨ O., Wang, Y., Viqueira P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 17 Gabarain, M., & Kong, H. (2019). Visions of UNaLab Follower Cities D6.5 Joint Vision Report Extract of pages related to Future Telling. www.UNaLab.eu. [28] A. Ruas, V. Clemence, B. Barroca, Y. Ulanowski, Comparison of cooling grey solutions in the sense-city urban demonstrator for adapting cities to heat waves, Urban Clim. 55 (2024), https://doi.org/10.1016/j.uclim.2024.101874. [29] A. Middel, V.K. Turner, F.A. Schneider, Y. Zhang, M. Stiller, Solar reflective pavements-A policy panacea to heat mitigation? Environ. Res. Lett. 15 (6) (2020) https://doi.org/10.1088/1748-9326/ab87d4. [30] I. Kousis, C. Fabiani, L. Gobbi, A.L. Pisello, Phosphorescent-based pavements for counteracting urban overheating – A proof of concept, Sol. Energy 202 (2020) 540–552, https://doi.org/10.1016/j.solener.2020.03.092. [31] Y. Liu, H. Ma, C. Zhang, X. Luo, Watering on porous pavement for improvement of environmental human thermal comfort in an ecological community in arid area: A case study in Lanzhou, China, Sustainable Cities and Society 85 (2022), https:// doi.org/10.1016/j.scs.2022.104081. [32] García-Melgar, P., Guerrero Delgado, Mc., Montero-Guti´ errez, P., Romero García, C., S´ anchez Ramos, J., & ´ Alvarez Domínguez, S. (2025a). Nature-based cool pavements for urban overheating mitigation: Experimental proof of concept. Building and Environment, 267, 112184. https://doi.org/10.1016/j. buildenv.2024.112184. [33] Ljung, L. (1998). System Identification (pp. 163–173). https://doi.org/10.1007/ 978-1-4612-1768-8_11. [34] T. S¨ oderstr¨ om, P. Stoica, Instrumental variable methods for system identification, Circ. Syst. Sig. Process. 21 (1) (2002) 1–9, https://doi.org/10.1007/BF01211647. [35] Thermal Energy System Specialists, L. (2024). TRNSYS software (18). [36] M.C. Guerrero Delgado, J. S´ anchez Ramos, S. ´ Alvarez Domínguez, Using the sky as heat sink: Climatic applicability of night-sky based natural cooling techniques in Europe, Energ. Conver. Manage. 225 (2020) 113424, https://doi.org/10.1016/j. enconman.2020.113424. [37] M.C. Guerrero Delgado, J. S´ anchez Ramos, M.C. Pav´ on Moreno, J.A. Tenorio Ríos, S. ´ Alvarez Domínguez, Experimental analysis of atmospheric heat sinks as heat dissipators, Energ. Conver. Manage. 207 (2020) 112550, https://doi.org/10.1016/ j.enconman.2020.112550. [38] M.C. Guerrero Delgado, J. S´ anchez Ramos, J.A. Tenorio Ríos, S. ´ Alvarez Domínguez, Falling-film as natural cooling technique: Modelling and energy impact assessment, Energ. Conver. Manage. 221 (2020) 113168, https://doi.org/ 10.1016/j.enconman.2020.113168. [39] ENVI-met GmbH. (2024). ENVI-met software (5.6). [40] NASA. (n.d.). NASA-STD-3001 Technical Brief. 2. [41] R. Defrin, M. Shachal-Shiffer, M. Hadgadg, C. Peretz, Quantitative Somatosensory Testing of Warm and Heat-Pain Thresholds: The Effect of Body Region and Testing Method, Clin. J. Pain 22 (2) (2006) 130–136, https://doi.org/10.1097/01. ajp.0000154048.68273.d8. [42] United States Environmental Protection Agency. (2020). EPANET: Application for Modeling Drinking Water Distribution Systems. P. García-Melgar et al. Energy & Buildings 343 (2025) 115945 18