Research on Sleep and Bedroom Thermal Environment of the Frail Older People in Summer and Winter

Abstract

This study aimed to examine the sleep and bedroom thermal environment of frail older people in summer and winter. The participants were nine frail older people (aged 79.1 ± 6.1 years) living in Nara Prefecture. Their activity levels were measured during the daytime and sleep. Air temperature and relative humidity were measured in the participants’ bedrooms. In both summer and winter, most participants turned off cooling or heating devices such as air conditioners before bedtime. Therefore, the bedroom temperature tended to be high in summer and low in winter, as with active older people in previous studies. The number of arousals and postural changes during sleep increased as the bedroom temperature increased in summer, suggesting that high bedroom temperature may negatively affect sleep quality. Furthermore, the participants went to the bathroom feeling cold at night in winter. It is also important to keep the bedroom and bathroom temperature high to prevent heat shock.