Background: With increases in global urbanization and global warming, there are corresponding increases in urban heat island effects. Heat wave disasters are occurring more frequently, posing direct and indirect mental health hazards to urban residents. The impact of high ambient temperatures on emotional health is a scientific problem that needs clarification.
Methods: Data collected through 386 valid emotions questionnaire and temperature data measured on heat wave days were analyzed using GIS, SPSS and MATLAB software to study the influence of heat waves on the negative emotions of middle-aged and older adults (over 40-years-old).
Results: The results indicate that the degree of influence of high temperatures on various negative emotions differs significantly, as some emotional responses tend to fluctuate while others steadily worsen. The progression of emotional responses is distressed > irritable > nervous > hostile. With increasing temperatures, phase-based changes in emotional states occur, with different emotional states corresponding to different temperature thresholds; the temperature thresholds for distress, nervousness, and hostility were shown to be 38°C/43°C, 40°C/44°C, 43°C, respectively.
Conclusions: Ambient temperatures exceeding 35°C have a significant negative impact on the emotional health of middle-aged and older adults. Irritability and nervousness monotonically increase, while distress and hostility tend to fluctuate. This study contributes to the prevention and management of the harmful effects of heat waves on emotions, providing basic information applicable to the design of layouts for urban green spaces to reduce the effects of urban heat islands.