Sleep stage and skin temperature regulation during night-sleep in winter

To clarify the thermally comfortable environment for satisfied sleep: we in vestigated the relationship between skin temperatures and sleep stages duri ng night-sleep in winter, summer and autumn. Four healthy young females ser ved as the subjects. The experiments were performed in a climate chamber un der three conditions: at 13 degrees C-RH70% with futon and blanket in winte r, at 20-18 degrees C-RH60% with futon and towelket in autumn and at 29 deg rees C-RH70% with towslket in summer. The subjects' skin temperature on the sole was lower until about 4 hours after lights off in winter than in autu mn and summer, and the percentage of st.2 was lower and st,4 was higher in winter than in autumn and summer, although the bed climate both in winter a nd autumn was much the same.