This study aimed to evaluate the bedroom thermal environment of older adults and to clarify the effects of the thermal environment on sleep using a longitudinal field survey. More than 90% of bedroom temperatures were higher than the recommended standard bedroom temperature for older people (23-27℃). However, most participants rated their bedroom environment as cool and comfortable. A high bedroom temperature, above29℃, decreased sleep quality, subjective sleep evaluation, and extended time in bed. Adjusting to an appropriate bedroom thermal environment is important for maintaining sleep quality and preventing excessive sleep duration.
