Supplemental Feeding and Thermal Comfort During Sleep in the Cold

¹ From the Stress Physiology Branch, Quartermaster Research and Development Center, Natick, Massachusetts

Six men were studied while sleeping in arctic sleeping bags at –34.5°C (–30°F). The men ate the usual three meals per day at conventional times plus a supplement of 0, 600 or 1200 Cal. 10 minutes before retiring. The composition of the supplement was 40% fat, 20% protein and 40% carbohydrate. The following measurements were made during the night: rectal temperature (T_r), mean skin temperature (T_s), toe temperature, and oxygen consumption (Vo₂). When a 600 or 1200 Cal. supplement was given T_r, T_toe and Vo₂ were significantly higher than with no supplement. T_s was not changed as a result of supplementation. There appeared to be no difference between the effect of a 600 or 1200 Cal. supplement. The supplement also reduced the number of periods of wakefulness and the subjective discomfort associated with cold.