Fifty-Three Hours of Total Sleep Deprivation Has No Effect on Rewarming From Cold Air Exposure

• Published in: Wilderness & environmental medicine 2012-12, Vol.23 (4), p.349-355
• Main Authors: Esmat, Tiffany A., PhD, Clark, Katherine E., PhD, Muller, Matthew D., PhD, Juvancic-Heltzel, Judith A., PhD, Glickman, Ellen L., PhD
• Format: Article
• Language: English
• Subjects: body temperature regulation; Body Temperature Regulation - physiology; Cold Temperature - adverse effects; Cross-Over Studies; Emergency; Environmental Exposure - adverse effects; Humans; hypothermia; Hypothermia - physiopathology; Male; Oxygen Consumption - physiology; Rectum - physiology; Skin Temperature - physiology; Sleep Deprivation - physiopathology; thermal sensation; Young Adult
• ISSN: 1080-6032; 1545-1534
• DOI: 10.1016/j.wem.2012.05.004

Objective 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). Methods 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. Results 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. Conclusions 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.