Sensitivity of Human Thermal Comfort Benchmarks to Background Temperature and Individual Factors: An Empirical Study in Wuhan, China

Individuals often adopt distinct behavioral patterns to adapt to different weather conditions. However, most studies on outdoor thermal comfort fail to consider weather variability and associated individual factors as interventions. This study conducted 12 days of field measurements and surveys across two residential areas in Wuhan, categorizing the sampled data based on background temperatures. Thermal benchmarks were developed for different age and gender groups under varying weather conditions, with comparative analyses conducted to evaluate differences in thermal comfort responses. With changes in outdoor temperature, the most comfortable thermal sensation in winter showed a wider fluctuation, ranging from 0.13 to 1.58, while in summer, it ranged between −1.76 and −1.18. The relationship between thermal sensation and comfort varied more significantly among different age groups in winter, while in summer, the differences were more evident between genders. As summer temperatures rose, younger and middle-aged individuals showed a greater increase in thermal sensitivity compared to the elderly. Similarly, males exhibited higher sensitivity than females. In terms of thermally acceptable temperatures, the upper limit was similar across age groups, around 35 °C. However, the lower limit varied as follows: the elderly had the lowest acceptable lower limit of around 0–3 °C; middle-aged individuals tolerated 4–7 °C higher; and young people tolerated 10–12 °C higher than the elderly. Between genders, the upper limit was also similar, but females tolerated 7–10 °C lower temperatures than males. In the context of outdoor thermal comfort studies in residential areas of Wuhan, the Universal Thermal Climate Index demonstrated better applicability than the Physiologically Equivalent Temperature. Overall, by analyzing thermal benchmark models for different demographic groups under varying weather conditions, this study enhances the understanding of how outdoor environments influence thermal comfort and provides valuable insights for targeted microclimate regulation and urban design strategies.