HUMAN CORE TEMPERATURE MINIMUM CALL BE MODIFIED BY AMBIENT THERMAL TRANSIENTS

By using dow linear thermal transients (+/-0.025 degrees C/min) of red uced amplitude (+/-3 degrees C around thermoneutrality), we were able to advance the minimum of human internal temperature (T-i) during noct urnal sleep. During experimental night the minimum of esophagal (T-es) and rectal (T-re) temperature were respectively advanced by 1.6 h (P < 0.01) and 2.6 h (P < 0.001) in comparison to reference night spent a t thermoneutrality. It must be emphasized that the provoked advance of nocturnal T-i minimum was not accompanied by any change in sleep late ncy, efficiency; SWS and REM sleep percentages. The result shows that appropriate ambient temperature transient changes could be used to mod ify the course of human T-i one of the major biological rhythms usuall y considered as resistant to sleep-wake rhythm manipulation.