Thermal preference effects on physiological responses and bedding system insulation selection during good quality sleep in the transitional season

Studies have proven that thermal preference significantly affects physiological parameters and thermal sensation. However, most of these studies were performed in the waking state and only a few were conducted in the sleeping state. In addition, skin temperature differed between the good and poor quality sleep. This study analysed the effects of thermal preference on physiological responses (skin temperature, human-bed interface temperature, bed microenvironment temperature, and heart rate) and bedding system insulation selection during good quality sleep at moderate temperatures in the transitional season. The results showed that the warm-preference subjects had higher skin temperature, human-bed interface temperature, bed microenvironment temperature, and bedding system insulation, but lower heart rate than the cold-preference subjects. Meanwhile, gender differences were apparent between subjects who had the same preference (warm/neutral/cold): the skin temperature, human-bed interface temperature, and bed microenvironment temperature of females were higher than those of males. Furthermore, the effects of body geometry parameters (height, weight, body mass index, body surface area, and specific surface area) on thermal preferences were not statistically significant. These results can provide research guidelines for designing thermal environments and personalised cooling/heating system for sleeping based on thermal preference difference, which can help improve the satisfaction rate of sleep thermal comfort and optimise building energy use strategies.