Effect of partial-body heating on thermal comfort and sleep quality of young female adults in a cold indoor environment

Abstract

This study evaluated the effectiveness of partial-body heating in improving the thermal comfort and sleep quality of young female adults sleeping in a cold indoor environment. A novel partial-body heating system (NPHS) was developed, consisting of three electrically heating pads in the feet, buttocks and shoulder regions with controllable surface temperatures, and the temperatures of the pads can be separately set on phone app. Eight female students were asked to sleep for 8 h in the CON (i.e., the NPHS with power off) and HEAT (i.e., the NPHS with power on) conditions randomly inside a climatic chamber. The chamber was controlled at 5 °C and 65% relative humidity. Physiological responses, including core and local skin temperatures, and heart rate, were recorded throughout all-night sleep. Participants' whole- and local-body thermal sensation, wetness and comfort sensations were evaluated. A subjective survey of sleep quality was also conducted after sleep. Results demonstrated that in comparison with CON, using HEAT showed significantly higher toe, calf and mean skin temperatures (p < 0.05), and remarkably improved whole- and local-body thermal and comfort sensations (p < 0.05), and provided a better sleep quality (p < 0.05). Besides, using NPHS did not induce body thermal stress evidenced by similar core temperatures and heart rate between HEAT and CON scenarios (p > 0.1). The present study shows that partial-body heating at the major body parts could effectively maintain thermoregulation, improve thermal comfort and provide a better sleep quality while sleeping in a cold environment.