Outdoor Thermal Comfort Research Articles

Improving Outdoor Thermal Comfort for Agricultural Workers: A Study of Heat Stress Relief Measures Using Sun Protection Lotions

The entire study was carried out on a group of 100 female farm workers at the CTAE university campus in Udaipur during the wheat crop harvesting season, with the aim of examining the effectiveness of various heat stress relief measures (sun protection lotion with different sun protection factors, SPF) in improving outdoor thermal comfort. The experiments were designed to assess the average skin temperature of Indian female farm workers under five fixed Wet Bulb Globe Temperature (WBGT) conditions (28, 29, 30, 31, 32°C), all falling within the heat stress category as per American Conference of Governmental Industrial Hygienists (ACGIH) standards. The mean skin temperature was determined using the Hardy du-bois 7-point model formula, which involved measuring the mean temperature of specific body parts of the 100 female farm workers. A variation of ± 0.5°C was considered due to the challenge of achieving precise thermal conditions in open field settings. The experiment aimed to evaluate the thermal and physiological responses of the participants. The findings revealed that the use of sun protection lotion alone resulted in increased cooling effect, thereby expanding the thermal comfort range. Additionally, the application of sun protection lotion alone reduced the mean skin temperature by 0.39, 0.38, 0.36, 0.30, 0.27°C by the end of the work period.

Health-Related Parameterization Evaluating Thermal Comfort in Urban Green Spaces: Data Sourced from a Global Database and Mapping at National Scale

Outdoor thermal comfort (OTC) is one of the most important issues for people exposed to urban green space (UGS). It is mainly evaluated by assessing equivalent meteorological factors that may combine and result in human responses of perceptions about comfortable vs. uncomfortable environments. The assessment of these responses is challenged by limits in a database that is powerful enough to support big-data analysis and an essential parameter that can evaluate health-related responses to OTC in urban forests. In this study, a meta-analysis was conducted by synthesizing studies of physiological and psychological health responses of green space (GS) visitors to meteorological factors in host cities on a global scale. A total of 15,000 numerical records about the psychological and physiological responses of UGS visitors were obtained from 105 papers across 68 global cities in 21 countries. A novel parameterization was developed to evaluate OTC by normalizing changes in health-related parameters and detecting their regressions against multiple meteorological factors. It was revealed that OTC resulted in more benefits in psychological health parameters than in physiological ones for UGS visitors worldwide. Globally, health-promoting OTC environments were more found in temperate countries than in countries subjected to other climates. People in Asian countries were indicated to live in environments with higher comfort that benefitted health states in cities at low latitudes. Thermal environments tended to be harsher and more challenging, mostly too chilling, in northern cities than in the south globally. A deep learning model using the ResNet algorithm was found to perform to an expected level with R2 as high as >70% and errors controlled generally lower than 0.01. Taking mainland China for instance, it was predicted that thermal environments in eastern cities of China highly challenged the psychological health of local UGS visitors across all seasons of the year. Northern cities of China were predicted to have satisfied thermal environments that benefited psychological and psychological health responses in spring. In summer, cities in West China were predicted to have comfortable thermal environments, and in winter, environments in the southwestern cities were more comfortable.

The Impact of Different Types of Trees on Annual Thermal Comfort in Hot Summer and Cold Winter Areas

Trees positively improve the annual thermal comfort of the built environment in tropical areas, where climate change is slight throughout the year. However, for areas with high changes in climate all year, the current studies have only explored the summer cooling performance of trees without the impact of different types of trees on annual thermal comfort, especially in cold seasons. Therefore, to quantify the impacts and scientifically guide the optimization of green space layout in hot summer and cold winter areas, this study selected Changsha City as the study area and analyzed how the annual thermal comfort is affected by evergreen trees and deciduous trees, which are two common types of trees in hot summer and cold winter areas. The analytical results indicated that the difference in the effect of deciduous and evergreen trees on outdoor thermal comfort was insignificant in summer, where the difference in the monthly mean PET for the three summer months was slight, being 0.28 °C, 0.14 °C, and 0.29 °C, respectively. However, evergreen trees greatly exacerbated winter cold compared to deciduous trees, with a monthly mean PET decrease by nearly 1.0 °C and an hourly PET reduced by up to 3.57 °C. The difference is mainly attributed to the absorption and reflection of solar radiation by the tree canopy, as well as the cooling and humidifying effect of the tree leaf. In hot summer and cold winter areas, outdoor thermal comfort is still in the “comfortable” and “slightly warm” acceptable stage despite the warming effect of deciduous trees in the spring and autumn seasons. Planting evergreen trees is an inevitable thermal mitigation choice for tropical areas. However, for the areas with high annual climate change, such as hot summer and cold winter areas in China, a change in empirical tree planting patterns and selecting deciduous trees where appropriate will improve year-round outdoor thermal comfort.

Influence of view factors on outdoor thermal comfort of residential areas in hot-humid regions.

Sky View Factor (SVF) is commonly used to describe the impact of urban geometry on the urban thermal environment. Shading effects from plants and buildings also exert a considerable influence. To investigate the influence of view factors on outdoor thermal comfort in residential areas, we employed the Physiological Equivalent Temperature (PET) and view factors (SVF, TVF, BVF) as indicators to determine outdoor thermal comfort and the quantity of shaded spaces. Thermal measurements collected from 13 points in Guangzhou, China, Our findings revealed that high TVF points exhibited more stable air temperature throughout the daytime, with average temperature differentials ranging 0.4-1.9°C lower than other points. Air temperature demonstrated a positive correlation with SVF (R2 = 0.53), while exhibiting a negative correlation with TVF (R2 = 0.45). Additionally, shading provided by plants and buildings manifests heterogeneity. At similar SVF levels, points predominantly shaded by plants (TVF > BVF) showcased lower Mean Radiant Temperature (MRT) and PET compared to points shaded mainly by buildings (BVF > TVF). The maximum reduction in air temperature and PET reached 1.1°C and 1.2°C, respectively. BVF exerted greater influence earlier in the morning, as solar altitude angle rises, the average thermal parameters of sites with BVF > TVF escalated rapidly until eventually surpassing sites with TVF > BVF. Last, superior thermal conditions were only ensured under high shading conditions. When the effective shading ratio of plants and buildings diminished (SVF > 0.3), the microclimate of measurement points might be impacted by the long-wave radiation from the underlying surface.

Comparative study of outdoor thermal comfort: Residents vs. tourists at Xi'an Ming Dynasty Ancient city wall scenic area

This study explores the thermal perceptions and comfort of residents and tourists at the Xi'an Ming Dynasty Ancient City Wall Scenic Area, addressing a gap in comparative outdoor thermal comfort studies in historical settings. Meteorological measurements and questionnaires collected between July 2019 and March 2021 analyze physical, individual, social, and psychological factors influencing thermal sensation, comfort, and acceptability across seasons. The RayMan model calculates Physiological Equivalent Temperature (PET), with data analyzed using SPSS 27.0. Results show Neutral PET (NPET) values of 17.1 °C for residents and 18.6 °C for tourists, and Preferred PET (PPET) values of 18.4 °C and 20.8 °C, respectively. Thermal Acceptability Ranges (TAR) are 13.5 °C–26.7 °C for residents and 15 °C–24.1 °C for tourists. Whether the measurement space contains water sources significantly affects temperature and humidity, while vegetation impacts wind speed. Physical factors predominantly affect perceptions, with individual factors becoming more important for tourists in winter. The findings provide insights for optimizing the thermal environment in scenic open spaces to enhance the comfort of both residents and tourists.

Optimization of urban morphology to enhance outdoor thermal comfort: A microclimate analysis

Optimization of urban morphology to enhance outdoor thermal comfort: A microclimate analysis

The Impact of Urban Roughness on Outdoor Thermal Comfort in Hot Arid Climate

The proportion of the world's population living in cities is rapidly increasing, presenting new challenges to the urban environment and quality of life. Among these challenges is the urban environment's impact on residents' outdoor thermal comfort, which can affect their health and well-being. Urban roughness, which includes building and street heights, has a significant impact on the thermal environment of urban areas. Changes in these factors cause variations in temperature distribution, wind speed, and humidity, which affect how people perceive thermal conditions. The research problem is the effect of urban roughness on outdoor thermal comfort in hot arid climate, specifically the height of buildings and the density, for a case study in (Al-Bab Al-Sharqi) in Baghdad city. Measurement method that employed the computer programs (Rino8 and Grasshopper) to calculate the thermal comfort index (UTCI) and its impact on various climatic variables. The findings revealed that the thermal comfort index and the climatic factors associated with it vary depending on the configuration of buildings.

Enhancing Outdoor Thermal Comfort with Shade-giving Trees in Humid Tropical Public Spaces: A Case Study of Alun-alun Bandung

Abstract Public spaces in urban areas function as places for visitors to socialize. These spaces are vital to the success of urban public activities. Adjustments to the microclimate in outdoor spaces have a significant impact on the thermal comfort of visitors. This research aims to assess visitors’ level of thermal comfort experienced in public areas, specifically in Alun-alun Kota Bandung and its surroundings. The site is divided into four distinct locations: (1) the central area; (2) the tree-shaded area; (3) the building-shaded area; and (4) the area with small vegetation. This study uses tools and simulation to analyze the relationship between outdoor activities and thermal comfort in its existing public space using quantitative methods. The study’s findings show that, while respondent responses vary across typologies, an analysis of the ENVI-met simulation reveals that they are nearly identical, indicating that it is generally warm. Furthermore, the slightly cool (-1 > PMV > -0.5) and neutral (-0.5 > PMV > 0.5) categories in typologies 2 and 4 produce distinct results. More shade-giving trees and the use of environmentally friendly materials that don’t reflect sunlight are two suggestions for enhancing the microclimate conditions for pedestrians’ thermal comfort in Alun-alun Kota Bandung.

A WRF-UCM-SOLWEIG framework for mapping thermal comfort and quantifying urban climate drivers: Advancing spatial and temporal resolutions at city scale

The capability to evaluate city-scale outdoor thermal comfort is crucial for understanding the public's experience of heat stress, especially during heat waves. Nevertheless, there remains a methodological gap in accurately mapping thermal comfort with high spatial and temporal resolutions in complex urban environment and in quantifying the contributions of various urban climate drivers, such as sky view factors and tree canopy fraction. To bridge this gap, we propose an innovative WRF-UCM-SOLWEIG framework that couples a mesoscale model with an urban microclimate model. Specifically, it integrates the Weather Research and Forecasting model coupled with the urban canopy model (WRF-UCM) and the Solar and Longwave Environmental Irradiance Geometry model (SOLWEIG). This framework is then applied to a densely populated tropical city in China, to quantify the impact of urban climate drivers on the Universal Thermal Climate Index (UTCI). The results reveal a significant diurnal variation in the impact of urban morphology. Notably, the most significant drivers affecting daytime UTCI are the impervious surface fraction and the tree canopy fraction, with maximum Pearson's correlation coefficients of 0.80 and -0.70, respectively. These findings suggest that urban heat mitigation strategies should prioritize on reducing impervious surfaces and enhancing shade management, alongside expanding urban forestry measures.

Enhancing the effectiveness of heat adaptation strategies through citizen science-based outdoor thermal comfort

Urbanization and intensifying climate change expose populations in cities to escalating heat stress and associated health risks. Mitigating these challenges require comprehensive assessments that combine quantitative and qualitative data to develop effective heat wave response strategies and policies. Previous research has primarily focused on thermal sensation measured by individual biometrics within specific locations. However, limitations in data collection across large areas often lead to the neglect of the influence of diverse urban environments. This may disregard the importance of regional variations and citizen engagement in formulating effective heat wave mitigation strategies. This study explored the impact of heat wave frequency and intensity across various urban spatial types and assessed thermal sensation vote (TSV) among residents of Suwon City using a citizen science approach. Temperature measurements and subjective heat sensations were collected over a three-year period using homemade temperature sensors. The analysis investigated thermal sensation differences across spatial types—open high rise, open low rise, compact mid-rise, urban park, and lake park—utilizing boxplots, and examined TSV variations by age using the R program localized smoothing methodology. Results indicate significant variations in TSV across different urban areas, particularly when temperatures exceeded 32 °C. The TSV was highest in the lake park areas (average thermal sensation vote +3.5) and was comparatively lower in the open high-rise and open low-rise areas (average thermal sensation vote +2.0). A significant age-related trend was observed, with the highest TSV reported by the 19–30 age group. Heat sensitivity appeared to decrease among participants aged 41 and over. These findings highlight the limitations of traditional top-down heatwave response strategies, which may not adequately account for spatial variations and individual experiences. Conversely, a bottom-up approach that leverages citizen science can inform the development of tailored and proactive strategies that consider a region's specific conditions.

Proposing design strategies for contemporary courtyards based on thermal comfort in cold and semi-arid climate zones

The relationship between urban geometry and microclimate is crucial in urban planning and climatology, significantly affecting outdoor comfort and energy consumption. Compact, dense buildings provide shading in summer, while openness is preferred in winter to maximize sunlight access. Courtyards, as climate-responsive structures, can create localized microclimates tailored to specific climatic conditions. Various components, including geometry, openness, orientation, wall materials, and green cover, influence the microclimate within a courtyard. While previous studies have primarily focused on hot and arid climates, there is a notable research gap concerning the thermal behavior of courtyards in cold and semi-arid regions. This study seeks to fill this gap by evaluating the impact of different courtyard geometries on outdoor thermal comfort specifically in semi-dry and cold climates by exploring optimal configurations for orientation, form, height-to-width ratios, and plan aspect ratios, the research offers strategies that improve both summer and winter microclimates. The study examined the combined effects of geometry and orientation on shading and wind speed in courtyards, modeling their influence on microclimates during warm summers and cold winters using ENVI-met software. Thermal performance indices, specifically PET and UTCI, were employed to assess the courtyards in Tehran. The findings reveal that a height-to-width ratio of 3:1 significantly improves thermal comfort, resulting in a UTCI difference of 19 °C. Furthermore, the model with a 2:1 plan aspect ratio exhibited a UTCI that was 6.7 °C lower than that of the 3:1 ratio. These findings provide valuable insights for designing contemporary courtyards that optimize thermal comfort in similar climates.

A sustainable and robust Janus film Inspired by the bird’s nest structure for efficient year-round outdoor thermal management

Janus structures combining radiative cooling and heating have attracted considerable interest for providing thermal comfort in dynamic environments. However, most of the strategies ignore the weak interfacial bonding due to the differences in material properties of the cooling and heating sides, which ultimately results in a lack of durability. Herein, inspired by the bird’s nest structure, we demonstrated a dual-mode Janus film with bonded interfaces through a simple vacuum-assisted filtration and PDMS modification. The unique structure of film ensures efficient thermal management including a sub-ambient temperature drop of ∼6.7 °C and a rise of ∼19.8 °C under direct sunlight irradiance. The cooling performance is activated by the synergistic enhancement with BaSO4 and BC porous networks, which exhibits high solar reflectivity (∼95.6 %) and MIR emissivity (∼95.2 %). The heating performance is derived from solar heating (∼71.6 °C at one sun irradiation) and Joule heating (∼88.6 °C at a low voltage of 2.5 V) as a complement, benefiting from the photothermal and electrothermal conversion of MXene. The cooling and heating can be easily obtained by flipping. In addition, the film maintains efficient cooling and heating even after being immersed in water and exposed to sunlight, thereby ensuring outdoor thermal management. Overall, this dual-mode Janus film shows great potential for regulating outdoor thermal comfort and alleviating the energy crisis.

WebMRT: An online tool to predict summertime mean radiant temperature using machine learning

Mean Radiant Temperature (Tmrt) is the most critical atmospheric variable influencing outdoor human thermal exposure and comfort in hot, dry environments. However, accurately quantifying Tmrt requires time-consuming field measurements with expensive equipment or complex, resource-intensive computations. We introduce WebMRT, an online tool to predict Tmrt using a data-driven approach. It features an intuitive interface using air temperature, shading status, and built environment features as predictors of Tmrt for a user-selected summer day, time, and location. Utilizing a tree-based ensemble model, WebMRT is trained on state-of-the-art human-biometeorological data collected by MaRTy using LightGBM after evaluating its performance against several candidate machine learning regressors. Feature engineering was applied to the day and time input, and two additional temporal features were derived: ‘Solar Altitude’ and ‘Minutes-from-Sunrise’. These inputs are integrated into the user interface, emphasizing simplicity and easy access for users at the frontend. After training the regressor on MaRTy datasets and employing k-fold cross-validation with ten folds, the model demonstrated strong predictive power (R2=0.92) with acceptable error (RMSE=3.43, MAPE=5.33) and bias (MBE=0.20). WebMRT also features optional fisheye photo uploads, processed using transfer learning techniques for image segmentation, further enhancing the tool's predictive accuracy, user experience, and applications towards climate action decision-making processes.

Outdoor thermal sensation scale through biometeorological assessment for semi-arid climate.

Extreme temperatures in urban areas cause discomfort leading to a rise in health risks, like heat-related mortality (hyperthermia). It is, hence, important to have a comfortable thermal environment. Assessing outdoor thermal comfort is challenging and complicated due to its dependencies on biometeorological and psychological factors. This study investigates the outdoor thermal comfort in Ahmedabad, a city with semi-arid climate in India through biometeorological measurements and thermal comfort surveys. The study carried out thermal comfort surveys of 1620 subjects spread across the city in 2022-23 covering all the seasons. The temperature and relative humidity were in the range of 21.6°C to 44.9°C and 8 to 86% respectively. About 43% of the subjects felt thermally comfortable during the survey. Based on the survey results, the annual neutral Physiological Equivalent Temperature (PET) obtained was 27.5°C, and the comfortable PET range was between 21.1°C and 33.9°C which covers a wide range. Neutral PET for summer and winter seasons obtained were similar, which indicates winters are getting milder and people of Ahmedabad are getting more adaptive towards warmer temperature. These results hold special significance as there is limited research on outdoor thermal comfort in such climate zone of India.

District-wise evaluation of meteorological factors and outdoor thermal comfort in India using UTCI – Insight into future climatic scenario

The study aims to comprehensively analyze outdoor meteorological conditions and thermal comfort across 592 districts in India, addressing the critical issues of thermal comfort which significantly impacts health, well-being and productivity. Given the anticipated global warming, understanding these factors becomes crucial, particularly for low-income populations who spend considerable time outdoors. While most previous studies in India have focused on indoor environments or on broad climatic regions, our research provides a granular analysis at the district level, incorporating future climate scenarios from 2050 to 2080. Using the Universal Thermal Climate Index (UTCI), our findings reveal that the northwestern part of India experiences ‘Strong’ to ‘Extreme’ heat stress, with temperatures exceeding 50 °C, while the Himalayan regions face ‘Strong’ cold stress, with temperatures dropping below -20 °C. The geographical distribution of UTCI classes shows that the western and central regions suffer from high thermal stress during summer afternoons, whereas coastal areas, benefiting from higher relative humidity and wind speeds, exhibit moderate UTCI values. The Himalayan regions consistently present lower UTCI values, indicating colder conditions. We have developed a district-wise climate atlas of India, mapping key environmental parameters and the outdoor thermal stress of UTCI values. The main objective of this study is to provide localized insights into how climate change will affect outdoor thermal comfort, facilitating informed decision-making for public health planning, energy infrastructure, and climate adaptation strategies across India.

Coupled Impact of Points of Interest and Thermal Environment on Outdoor Human Behavior Using Visual Intelligence

Although it is well established that thermal environments significantly influence travel behavior, the synergistic effects of points of interest (POI) and thermal environments on behavior remain unclear. This study developed a vision-based outdoor evaluation model aimed at uncovering the driving factors behind human behavior in outdoor spaces. First, Yolo v5 and questionnaires were employed to obtain crowd activity intensity and preference levels. Subsequently, target detection and clustering algorithms were used to derive variables such as POI attractiveness and POI distance, while a validated environmental simulator was utilized to simulate outdoor thermal comfort distributions across different times. Finally, multiple classification models were compared to establish the mapping relationships between POI, thermal environment variables, and crowd preferences, with SHAP analysis used to examine the contribution of each variable. The results indicate that XGBoost achieved the best predictive performance (accuracy = 0.95), with shadow proportion (|SHAP| = 0.24) and POI distance (|SHAP| = 0.12) identified as the most significant factors influencing crowd preferences. By extrapolation, this classification model can provide valuable insights for optimizing community environments and enhancing vitality in areas with similar climatic and cultural contexts.

Determination of outdoor thermal comfort thresholds for hot and semi-arid climates: A field study of residential neighbourhoods in Jaipur city

Outdoor thermal comfort (OTC) plays a vital role in enhancing the livability and well-being of urban residents, making it an essential area of research, particularly in the context of climate change. However, few studies have specifically focused on hot and semi-arid regions, especially within residential environments. This study seeks to address this gap by assessing OTC in various residential areas classified as Local Climate Zones (LCZs), ensuring a diverse range of survey locations to evaluate people's comfort and stress levels. Using the Thermal Sensation Vote (TSV) index, the study calibrated the Physiologically Equivalent Temperature (PET) scale for hot and semi-arid climates. In Jaipur, micrometeorological data was monitored alongside thermal perceptions, resulting in 2,428 valid responses gathered during both summer and winter seasons, between 09:00 and 21:00 h, when outdoor activity is common. The analysis revealed that microclimate parameters significantly influence thermal sensations in outdoor environments. Respondents showed high tolerance levels during summer, with variations in thermoneutrality, acceptability, preferences, and comfort across different built typologies. The threshold values identified in this study offer valuable insights for urban planners and designers, enabling them to enhance outdoor thermal comfort during the planning stages, ultimately creating more comfortable and livable urban spaces for residents.

Evaluating Urban Heat Island Mitigation Strategies in Rajshahi, Using ENVI-Met: A Remote Sensing Approach

The Urban Heat Island (UHI) effect is a critical environmental challenge in the 21st century, intensified by rapid urbanization and industrialization. This study focuses on Rajshahi, a rapidly urbanizing city in Bangladesh, where the UHI effect has already begun to manifest significantly. Utilizing ENVI-met software, a comprehensive analysis was conducted to evaluate the effectiveness of urban vegetation strategies, such as green roofs and street planting, in mitigating local temperatures and improving outdoor thermal comfort in Rajshahi's Central Business District. The findings reveal that these mitigation strategies can reduce air temperatures by up to 10 Kelvin, providing substantial cooling benefits. This research highlights the importance of integrating green infrastructure into urban planning to combat the UHI effect, enhance sustainability, and improve the overall livability of urban environments. The study offers valuable insights and practical recommendations for urban planners and policymakers, aiming to foster resilient and sustainable urban development in rapidly growing cities like Rajshahi.

Could residential air-source heat pumps exacerbate outdoor summer overheating and winter overcooling in UK 2050s climate scenarios?

The UK government promotes heat pumps to replace gas boilers in the residential sector as a vital part of its strategy to achieve Net Zero by 2050. As climate change intensifies, heat pumps, traditionally used for heating, will also play a role in cooling to address indoor heat risks that threaten public health and increase energy demands. However, air-source heat pumps (ASHPs) might unintentionally exacerbate summer overheating and winter overcooling in residential neighbourhoods. This study uses a multi-scale modelling approach, combining SUEWS and EnergyPlus, to assess the impact of ASHPs on outdoor temperature in two idealised UK low-rise residential neighbourhoods under 2050s climate scenarios. Results show that in summer, ASHPs increase median anthropogenic heat emission by up to 19.3 W m-2 and raise local median 2 m air temperature by up to 0.12 °C in an idealised London neighbourhood. In winter, replacing gas boilers with ASHPs for heating reduces anthropogenic heat emissions by up to 11.1 W m-2 and lowers local air temperatures by up to 0.16 °C in London. The research shows that conventional waste heat calculations from air-conditioning can overestimate anthropogenic heat emissions by up to 86 %, and cooling entire building rather than just occupied rooms can increase energy consumption by 68 %. Although temperature changes will vary across UK cities, the response of air temperature to anthropogenic heat change is generally consistent. The study enhances understanding of role of ASHPs in the UK's net zero target for 2050, highlighting the importance of balancing outdoor and indoor thermal comfort when considering the wide use of ASHPs.

Evaluating thermal comfort indices for outdoor spaces on a university campus

This study evaluates the applicability of three thermal comfort indices—Physiologically Equivalent Temperature (PET), Standard Effective Temperature (SET), and Universal Thermal Climate Index (UTCI)—in various outdoor environments on the campus of Xi’an University, China. Meteorological data were collected on sunny days using a portable weather station at a height of 1.5 m, and subjective questionnaires were administered to 25 healthy university students over three months to gather Thermal Sensation Votes (TSV) and Thermal Comfort Votes (TCV). The study was conducted at four distinct outdoor locations: a lakeside area (Location 1), a shaded path (Location 2), a sports field (Location 3), and a plaza (Location 4). PET, SET, and UTCI values were calculated from the collected data using Rayman software. The analysis revealed significant differences in thermal comfort across the four locations, with the highest proportion of subjects feeling hot at the sports field (54.4%) and the highest proportion feeling cold at the lakeside (39%). The shaded path had the highest proportion of subjects feeling comfortable (79.4%), while the lakeside had the lowest (60.1%). The results indicated that SET underestimated thermal sensation at Locations 1, 3, and 4, necessitating calibration. PET was suitable for Locations 2, 3, and 4 but failed to reflect the thermal sensation at Location 1 due to prolonged sun exposure. In contrast, UTCI demonstrated applicability across all locations. To enhance accuracy, revised indices SET’ and PET’ were formulated using the mean-median method, providing more precise thermal comfort assessments. These findings underscore the limitations of SET and PET under specific conditions and highlight the robustness of UTCI, offering valuable insights for urban planning and design aimed at improving outdoor thermal comfort and well-being.