Accession Number:

ADA128021

Title:

Metabolic and Vasomotor Insulative Responses Occurring on Immersion in Cold Water,

Descriptive Note:

Corporate Author:

ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Report Date:

1983-04-01

Pagination or Media Count:

39.0

Abstract:

The metabolic heat production of twenty male subjects undergoing total immersion in water between 36 C and 20 C was measured as functions of time and water temperature. These were converted to explicit linear functions of core Tre and mean skin Tsk temperatures for each individual immersion. The functions were used to define planes of thermogenic activity which allowed comparison of the threshold and magnitude of shivering between individuals of any morphological group. The thermogenic planes showed a much steeper slope with respect to the Tsk axis for small. Thin men than for large, fat men, while men of average weight and fat composition exhibited an intermediate slope. Small, lean men also exhibited thermogenic planes having steeper slopes with respect to the Tre axis than did average men. Whole body insulation was evaluated for each individual immersion. Analysis showed that small, lean men maximally vasoconstrict at higher bath temperatures than did large, fat men and that small, lean men were unable to maintain their maximum whole body insulation before the latter attain their maximum insulation. The decline in insulation, seen above a certain critical metabolic level, reflects the increasing muscle blood flow necessary to support active shivering this critical level appears to be 150 W in small to average size subjects.

Subject Categories:

  • Anatomy and Physiology
  • Stress Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE