Thermal and metabolic responses of sleep deprivation of humans during acute cold exposure.

Purpose: This investigation evaluated the effects of 33 h of sleep deprivation on the thermoregulation in 12 male and female subjects (26.6 +/- 6.4 yrs) during 180 min of cold exposure in 12 degrees C air.

Methods: Subjects underwent two cold air trials (CAT): one following a normal night of sleep (i.e., 6-8 h) (CON); and one following 33 h of sleep deprivation (SDEP). Rectal temperature (Tre), mean skin temperature (Tsk), heat production (HP), and tissue insulation (Iti), were measured at 5, 15, 30, and every 30 min thereafter.

Results: ANOVA revealed no significant differences (p > 0.05) between CON and SDEP for Tre, Tsk, HP, and Iti. A main effect for time was demonstrated for Tre, Iti, HP, and Tsk. A trial x time interaction for Tre and Tsk (p = 0.021) was demonstrated.

Discussion: Significant interactions were demonstrated for Tre and Tsk, but post hoc analysis determined no differences between SDEP and CON. This may have been due to the length of the sleep deprivation, cold stressor, or a combination of the two. There were also no overall differences in HP or Iti between SDEP and CON. Further research in this area is needed to evaluate the effects of sleep deprivation during acute cold exposure.