Thermal experience improvement and thermal requirement difference in bed warming conditions

The human body is exposed to nonuniform thermal environment due to asymmetric bedding coverage of head and covered body. The purpose of the study is to investigate the thermal requirement difference of local body parts during sleep. Experiments were performed both in bed warming and non-bed warming conditions. Twelve healthy postgraduates were recruited as subjects. The thermal states on different local body parts of subjects were obtained via objective measurement and subjective questionnaires. The results showed that thermal comfort during sleep in winter was not in accordance with the thermal neutral state. In order to achieve overall thermal comfort condition, discrepant thermal sensation should be kept be-tween the head and covered body, besides, the disparity in skin temperature was 1.5°C and in TSV was 0.5 between posterior and lateral body part. The study has implications in the energy saving design of the coupled sleeping thermal environment in winter.