Evaluation of outdoor thermal environment coupled with climate change and human factors

Against the backdrop of global warming and frequent extreme weather, high temperature and heatwaves are becoming increasingly frequent, significantly increasing the thermal health risks for people working and engaging in outdoor activities. Quantifying the relationship between outdoor heat stress and the maximum permissible exposure time of personnel is of great practical significance for safeguarding the thermal health of outdoor activity personnel. Taking Jinan City as an example, the study clarified the response pattern of outdoor heat stress with climate change by constructing future meteorological datasets for different time periods. The effects of outdoor heat stress and personal factors on the maximum permissible exposure time (tmax) were investigated, and the prediction models of the tmax for people under different activity states were proposed. The results showed that by the end of the 21st century, the maximum monthly mean Universal Thermal Climate Index (UTCI) at different moments in the shade and sun scenarios will be about 39°C and 45°C, respectively. For a certain activity level, the tmax decayed exponentially with increasing UTCI. And for any activity level, the tmax for females was significantly smaller than that for males.