Energy cost, fluid and electrolyte balance in subarctic survival situations

Abstract
In two experiments a total of 12 men were subjected to 5 days of starvation under survival conditions in the winter subarctic. They wore flying clothing rated at 3.5 clo. The caloric cost, as calculated from oxygen consumption, was 2,300 kcal/m2 for the first day and 2,000 kcal/m2 for subsequent days at ambient temperatures of -30 C. At -10 C the cost of subsequent days fell to 1,500 kcal/m2. The subjects lost 8% of body weight but regained 5% body weight after 5 days refeeding on a barely maintenance diet. One-third of the original (8%) weight loss was due to an isotonic contraction of extracellular fluid. Changes in heart rate, pulse pressure, and hematocrit consistent with this fluid contraction were observed. Although the water intake did not exceed the 5-day urine volume (5 liters), the subjects did not experience thirst until after return to the warm. Note:(With the Technical Assistance of William P. Esser and Kermitt R. Skrettingland) caloric cost; cold exposure; electrolyte balance in starvation; fasting; fluid balance in starvation; IMP, integrating motor pneumotachograph; fat carbohydrate and protein catabolism in cold exposure and starvation; cold diuresis; sodium, potassium and acid-base balance in acute starvation Submitted on June 3, 1963