Metabolic response to respiratory heat loss-induced core cooling.

Journal Article (Journal Article)

To study the phenomenon of isolated core cooling, four resting men breathed cooled helium-oxygen (T in = 14 +/- 2 degrees C, 40-60% relative humidity) in a warm hyperbaric chamber at pressures equivalent to 640, 1,000, and 1,400, and 1,800 ft seawater (fsw). Rectal temperature (T re) fell by 0.43 +/- 0.13 degrees C at 640 fsw to 0.98 +/- 0.15 degrees C at 1,800 fsw after 60 min. The rate at which T re fell was linearly related to the product of inspired gas density times specific heat. The metabolic response (VO2) to this isolated core cooling was more closely related to the rate of fall in T re than to the magnitude of this fall. A distinct threshold temperature, below which a rise in VO2 would occur, was not demonstrable. However, when the rate of fall of T re exceeded 0.70 degrees C . h-1, VO2 increased above base line, in spite of high skin temperatures that may have blunted the VO2 response. When VO2 did increase, its net benefit on thermal homeostasis was negated by the associated rise in pulmonary ventilation and its attendant increase in respiratory heat loss. Breathing cool helium-oxygen under hyperbaric conditions can rapidly lower deep body temperature, even in the presence of a warm body surface.

Full Text

Duke Authors

Cited Authors

  • Piantadosi, CA; Thalmann, ED; Spaur, WH

Published Date

  • April 1, 1981

Published In

Volume / Issue

  • 50 / 4

Start / End Page

  • 829 - 834

PubMed ID

  • 7263366

International Standard Serial Number (ISSN)

  • 0161-7567

Digital Object Identifier (DOI)

  • 10.1152/jappl.1981.50.4.829


  • eng

Conference Location

  • United States