COMPARISON OF PHYSIOLOGICAL CHANGES DURING LONG TERM IMMERSION TO NECK LEVEL IN WATER AT 95, 85, AND 75F
NAVAL MEDICAL RESEARCH INST BETHESDA MD
Pagination or Media Count:
The experiment was designed to evaluate the physiological changes which result from immersion of subjects in water to neck level for 24 hours at water temperatures of 95, 85, and 75F. It had previously been determined that immersion of subjects in water below 95F resulted in a heat loss from the body which was compensated by an increase in metabolic rate. Other changes in blood morphology and blood electrolytes had been shown to occur concomitantly with increased urinary excretion of water and electrolytes. Since the previous studies had been carried out over a relatively short period of time, the present experiments were designed to evaluate such changes over a 24-hour period, not only at 95F water temperature but at lower water temperatures as well. It was found that the three subjects increased their metabolic rate when immersed in 85F water and were able to maintain a normal deep body temperature over a 24- hour period. When immersed in the 75F water, the increased oxygen consumption due to shivering was insufficient to maintain deep body temperature. In addition, the physiological discomfort of immersion at 75F and the spiritual failure of those subjects caused the experiments to be terminated within 12 hours. The changes in the morphology and electrolyte content of the blood together with the hemoconcentration were associated with increased urinary water and electrolyte excretion and were progressive with time.
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