Optimizing bedroom thermal environment: A review of human body temperature, sleeping thermal comfort and sleep quality

Thermal environment may affect sleep quality and sleeping thermal comfort at the same time. Up to now, there is no direct evidence or physiological theory can prove the idea that thermal comfort equal to good sleep quality, but how to balance the relationship between them is often ignored when designing thermal environment. This review took body temperature distribution as a bridge for the connection of sleep quality and sleeping thermal comfort. At first, we reviewed the quantitative relationships among thermal environment, body temperature, sleep quality and sleeping thermal comfort, and then based on the idea of reverse derivation, a recommended design process for bedroom thermal environment was proposed. Each step of the process corresponded to the impact mechanism described above. The review results showed that, body temperature distribution was closely related to both sleep quality and thermal comfort, and thus it was suitable to be used as a bridge between them; body temperatures fluctuated dynamically during sleep, and thus heat transfer and thermal regulation models should be used to describe them; most current sleep researches regarded skin temperature as the representative value of body temperature distribution, yet core body temperature needs to be paid more attention on in the future because it was more closely related to sleep rhythm; furthermore, in addition to young people, subjects of more age groups should be tested to enrich China's sleep research database. In general, it's theoretically possible to guarantee both sleep quality and sleeping thermal comfort, and this review can be used as a reliable reference for bedroom thermal environment design.