Pattern of cold adaptation in women divers of Korea (ama)
Hong, S.K.
Federation Proceedings 32(5): 1614-1622
1973
ISSN/ISBN: 0014-9446 PMID: 4705209 Document Number: 5591
Pattern of cold adaptation in ama who daily dive in water of 27-28 C in summer and of 10 C in winter has been systematically studied from 1959 to 1969. The total extra heat loss for diving work is estimated to be 1,000 kcal/day throughout the year. The following adaptive phenomena to cold are found in Korean ama as compared with nondiving Korean women: 1) a consistent, reversible increase in basal metabolic rate of ama in winter (i.e., metabolic adaptation), which seems to be associated with increased utilization of thyroid hormone; 2) a very small (but significant) increase in Vo, in response to exogenous norepinephrine in winter; 3) a lower critical water temperature at a comparable subcutaneous fat thickness throughout the year (i.e., insulative-hypothermic adaptation); 4) a significantly greater maximal thermal insulation at a comparable subcutaneous fat thickness throughout the year; 5) a lower heat flux from the limb coupled with a higher blood flow throughout the year during whole-body immersion in water of critical temperature, suggesting a more efficient counter-current heat exchange system in the limb; and 6) a lower finger skin temperature and blood flow in winter during hand immersion in 6 C water (i.e., vascular adaptation). These results indicate that the basic pattern of cold adaptation in man is qualitatively similar to that observed in other homeothermic animals.
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