Sleep during prolonged heat exposure in man.

The interaction between sleep and thermoregulation was studied in man during prolonged heat exposure. Acclimation effects were observed in thermoregulation, the sweating rate increasing to a maximum in the first nights of heat exposure and then declining until the end of the period. No acclimation effects were found in sleep parameters. REM sleep was the sleep stage most affected by the heat load. During recovery, after effects in sleep parameters were also observed.