Human thermoregulatory responses during serial cold-water immersions

J Appl Physiol (1985). 1998 Jul;85(1):204-9. doi: 10.1152/jappl.1998.85.1.204.

Abstract

This study examined whether serial cold-water immersions over a 10-h period would lead to fatigue of shivering and vasoconstriction. Eight men were immersed (2 h) in 20 degrees C water three times (0700, 1100, and 1500) in 1 day (Repeat). This trial was compared with single immersions (Control) conducted at the same times of day. Before Repeat exposures at 1100 and 1500, rewarming was employed to standardize initial rectal temperature. The following observations were made in the Repeat relative to the Control trial: 1) rectal temperature was lower and heat debt was higher (P < 0.05) at 1100; 2) metabolic heat production was lower (P < 0.05) at 1100 and 1500; 3) subjects perceived the Repeat trial as warmer at 1100. These data suggest that repeated cold exposures may impair the ability to maintain normal body temperature because of a blunting of metabolic heat production, perhaps reflecting a fatigue mechanism. An alternative explanation is that shivering habituation develops rapidly during serially repeated cold exposures.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Blood Glucose / metabolism
  • Body Temperature Regulation / physiology*
  • Cold Temperature / adverse effects*
  • Humans
  • Immersion / physiopathology*
  • Male
  • Norepinephrine / blood
  • Oxygen Consumption / physiology
  • Shivering / physiology
  • Vascular Resistance / physiology
  • Vasoconstriction / physiology

Substances

  • Blood Glucose
  • Norepinephrine