Fifty-three hours of total sleep deprivation has no effect on rewarming from cold air exposure

Sleep deprivation and cold air exposure are both experienced in occupational and military settings but the combined effects of these 2 stressors is unknown. The purpose of this study was to determine the effects of 53 hours of total sleep deprivation on thermoregulation during the rewarming phase (25°C air) after acute cold air exposure (10°C air).

Eight young men underwent 2 trials in which they either received 7 hours of sleep at night or were totally sleep deprived. On 3 consecutive mornings, the subjects underwent 2 hours of cold air exposure followed by 2 hours of rewarming. Rectal temperature, mean skin temperature, oxygen consumption, and thermal sensation were measured.

Rewarming from acute cold air exposure caused a decline in rectal temperature (~0.5°C) each day but this was not different between subjects who were totally sleep deprived and subjects who received 7 hours of sleep at night. During this same period, mean skin temperature increased (from ~22°C to 27°C), oxygen consumption decreased (from ~7 to 4 mL·kg(-1)·min(-1)), and the participants felt warmer.

Under the conditions of the present study, sleep-deprived persons are not at a greater risk for a decline in rectal temperature (ie, a hypothermic afterdrop) during rewarming from cold air.