Investigation of the differences in bed microclimate and thermal comfort between school-aged children and adults during sleep onset latency

The thermal comfort experienced during sleep onset latency (SOL) significantly influences overall sleep quality. While most previous studies have primarily focused on thermal comfort during actual sleep, this study aims to investigate and compare the bed microclimate and thermal comfort during SOL in school-aged children and adults, taking into account their differing physiological characteristics and thermal preferences under various sleep thermal conditions. Fourteen school-aged children and fourteen adults participated in two experiments conducted under winter conditions (8 °C and 11 °C), as well as two experiments under transitional conditions (21 °C and 24 °C). Each experiment lasted 60 min, with continuous monitoring of skin temperatures and bed microclimate throughout the duration. Subjective assessments of thermal perception were collected after each experiment. The experimental results indicate that the difference in skin temperature (T_sk) between school-aged children and adult subjects is more pronounced under winter conditions, underscoring the importance of considering age-related differences when designing optimal sleep thermal environments, particularly during colder months. The comfortable range for T_sk among school-aged children is identified as 34.4–35.4 °C, while for adults it is slightly narrower at 34.3–35.0 °C. Additionally, the comfortable range for bed temperature (T_bed) is found to be between 30.8 and 33.8 °C for school-aged children compared to a range of 31.0–33.2 °C for adults. Furthermore, it was observed that the comfort range of T_sk is approximately 0.4–1.3 °C higher in the sleep environment than in the active daytime environment. These findings provide valuable insights that can inform the design of effective thermal environments aimed at enhancing SOL in both children and adults, thereby contributing to reduced economic costs while improving energy efficiency.