Research on Patterns and Characteristics of Winter Individual Experienced Temperatures (IETs) of Rural Older Adults: A Case Study in Henan, China

Experienced temperatures significantly affect the health of older adults due to irreversible physiological declines. In heat exposure studies, temperature measurements in specific spaces cannot fully capture individuals’ thermal experience in daily life, as people naturally and actively move between spaces with distinct thermal environments. The dynamic temperature experienced by rural older individuals in complex daily lives remains unclear, which is crucial for understanding its impact on health. This study discusses the concept of individual experienced temperatures (IETs) and investigated the characteristics and patterns of older adults’ IET in rural China during winter. A new method and equipment for longitudinal and noninvasive IET monitoring were developed and collected 157,800 IET data points, which were organized into 362 valid datasets. The data was gathered in China’s cold climate zone and hot summer cold winter (HSCW) climate zone from December 2023 to February 2024. The results revealed that local climate and weather had a significant impact on older adults’ IET. Cold waves reduced IET, while the effects were alleviated by thermal adaptation behavior of older adults. Diurnal IET was categorized into three patterns (stable group, active group, and moderate group) using K-means clustering analysis. The “stable group” was characterized by frequent IET fluctuations within a narrow and low temperature range. The “active group” was characterized by drastic IET fluctuations and high diurnal temperature range. The “moderate group” was characterized by low fluctuation frequency. For each participant, the majority of diurnal IET concentrated in one or two patterns. The IET of older adults exhibited significant individual variation. This research also discussed the significance of IET in comparison to traditional heat exposure studies. It highlights the dynamic and individualized nature of people’s heat exposure, contributing to the body of knowledge in this field. Furthermore, it provides greater accuracy and robustness in the result when assessing the health risks associated with exposure to varying temperatures. Recommendations for IET improvement were proposed from the perspectives of built environment optimization and policy support.