A comprehensive review of thermal comfort evaluation methods and influencing factors for urban parks

Urban parks play an important role in alleviating the negative impacts of global climate change and benefit urban thermal resilience. A well-designed thermal environment in urban parks contributes to people's health and attracts more individuals to engage in outdoor activities. However, the application of thermal comfort evaluation methods to urban parks and the effect of influencing factors on thermal comfort have not been deeply explored. This study aims to provide a comprehensive review of the evaluation and influencing factors of thermal comfort in urban parks. A total of 72 relevant articles were selected through screening. The results indicate that PET (Physiological Equivalent Temperature) and UTCI (Universal Thermal Climate Index) are commonly used for evaluating thermal comfort in urban parks. However, the reference ranges used by PET and UTCI do not quite match the actual neutral temperature ranges well. The combination of different landscape factors such as trees, water bodies, and grass can provide varying impacts on thermal comfort. Compared to winter, most people are more sensitive to temperature changes, and the neutral ranges of PET and UTCI are relatively narrow in summer. Moreover, people often adopt related adaptive behaviors (such as increasing activity intensity, moving away from sunny or warm areas, and drinking water) to alleviate thermal discomfort. This literature review emphasizes the calibrations of PET and UTCI reference ranges considering the landscapes, climate, and personal characteristics of urban parks. It provides insights for the evaluation, design, and service, aiming to develop the full potential of thermal comfort in urban parks.