In a study presented in 2017, the Personal Health Care Research Laboratory of Kao Corporation (President and CEO, Michitaka Sawada) reported that moderate warming of the periocular skin region before bedtime improved the quality of sleep, e.g., ease with quickly falling asleep, in individuals with mild sleep difficulties *1 ,*2 . In the present study, Kao researchers focussed on body temperature, which is known to be closely related to sleep, and attempted to clarify the mechanism related to ease with falling asleep. Our results indicated that heat loss from the body is enhanced as skin temperature of the hands and feet becomes elevated by moderate warming of the periocular skin region (Fig. 1). That physiological change is similar to body changes related to falling asleep and considered likely to have a favorable effect on sleep initiation.