Assessing outdoor thermal comfort and activities of the elderly in urban parks: A case study in Xiamen, China

Abstract The elderly are the primary users of urban parks, and thermal environment plays an important role in quality of life. However, existing research on outdoor thermal comfort (OTC) has given limited attention to the elderly in hot-summer and warm-winter (HSWW) regions. In this study, field surveys, including meteorological measurements, questionnaires, and activity observations were conducted to assess OTC of the elderly. Physiological equivalent temperature (PET) was calculated, and the results indicated that: 1) Neutral PET (NPET) of the elderly was 23.5℃, with neutral PET range (NPETR) of 19.01–27.98℃. Preferred PET was 25.5℃, and 80% thermal acceptability range (TAR) was 7.2-21.45℃. 2) Among influencing factors, physical factors were the most important, followed by psychological, individual, and social factors. 3) A multiple linear regression model was used to determine the weights of factors affecting thermal sensation, establishing a high-performance predictive model. 4) In spring and autumn, PET and attendance exhibited a quadratic relationship. In summer, attendance was negatively correlated with PET, and it was very low when PET exceeded 37°C. 5) The elderly primarily alleviated discomfort by regulating thermal radiation when facing thermal stress. These findings provide valuable references for the optimized design of urban parks, aiming to better meet thermal demands of the elderly and promote healthy aging.