Acclimatization to Cold in Antarctica as shown by Rectal Temperature

Journal/Book: Reprinted from Nature Vol. 193 No. 4818 p. 886 only-March 3 1962. 1962;

Abstract: Antarctic Division Department of External Affairs 187 Collins Street Melbourne Victoria Australia. ANIMALS acclimatized to cold have been shown to maintain their deep body temperature at normal levels under conditions cold enough to induce hypothermia in unacelimatized animals. Similar studies on men presumed to be acclimatized have given conflicting results. Some investigations have suggested that there is an improved ability to maintain rectal temperature others have shown no change while yet another has shown a diminished ability to maintain rectal temperature. Such conflicting findings have led some workers to the conclusion that man does not acclimatize to cold possibly for the reason that he is rarely exposed to sufficient cold stress to induce acclimatization. It was therefore thought desirable to investigate the effect of residence in the seasonally varying but always cold climate of Antarctica on men's responses to a test cold exposure. Four members of the 1958-60 party of the Australian National Antarctic Research Expedition to Mawson (lat. 67° 36´ S. long. 62° 53' E.) were exposed to a standard cold stress before during and after a year in the antaxetic. The standard cold stress consisted of a 95-min. exposure to an air temperature of 50° F. while the subject rested naked on a nylon-mesh mattress. During this exposure and during the last 1/2 hr. of a 1-hr. control period under blankets that preceded it the skin temperature at five sites and the rectal temperature were measured every 5 min. and the metabolic rate was determined every 15 min. The time of day and food and exercise preceding the exposure were standardized. The ambient conditions to which the subject was exposed (air temperature humidity air movement and mean radiant temperature of the surroundings) were measured during every exposure Five series of these tests were carried out and in every series the same four subjects were exposed twice making eight exposures per series and forty exposures for the whole study. Series 1 was done in Melbourne in December (summer) 1958 immediately before sailing for the antarctic; series 2 3 and 4 were done at Mawson in 1959 in autumn spring and summer respectively; and series 5 was done a week after returning to Melbourne in March (autumn) 1960 one month after the expedition ship had left antarctic waters. ... ___MH

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Acclimatization to Cold in Antarctica as shown by Rectal Temperature - Response to a Standard Cold Stress