Sex difference in body temperature and thermal perception during nighttime sleep: A time series analysis

Abstract

Sex difference stands as a crucial factor necessitating consideration in personalized sleeping thermal environment control. However, there has been little exploration about sex differences in body temperature and thermal perception during sleep. Based on data from a winter sleep experiment (16, 20, 24°C) involving 14 young participants (7 males, 7 females), a time series analysis of the dynamic body temperature rhythms throughout the night was conducted, revealing sex-specific patterns in local skin temperature and core body temperature. Additionally, the sex difference in the thermal perception votes recalled by subjects after waking was analyzed. The results showed that: (1) For both sexes, the skin temperatures reached to stable condition in 2–3 h after getting into bed, and core temperatures changed over the entire night. The average value and maximum increase value of overnight skin temperature at distal parts (hands and feet) were prone to sex differences, which become more pronounced at lower ambient temperature. (2) Females’ core body temperature was generally higher than that of males at the same time points. Due to the influence of estrogenic hormones, the maximum reduction in core body temperature during sleep was typically smaller in females than in males, with significant differences (p < 0.05) observed under the 16 °C and 24 °C conditions. (3) Females exhibited higher psychological demands for the sleeping thermal environment than males. Males reported feeling more comfortable than females in the 16 °C and 20 °C conditions. Additionally, males generally showed greater acceptance and satisfaction with all thermal environments compared to females. Overall, the creation of personalized sleeping thermal environments must account for sex differences in both skin temperature and core body temperature. This study provides a theoretical foundation for personalized sleeping thermal environment design from the perspective of thermo-physiology.