Reduced set-point temperature in young men after prolonged strenuous exercise combined with sleep and energy deficiency.

The effects on body temperature of 3-4 days of continuous military exercise combined with energy and sleep deficiency, at rest and in response to an exercise test (45% of VO2max for 30 min) and the following recovery, have been studied in fifteen young male cadets. During the course, at rest before exercise, rectal temperature was reduced by 0.57 +/- 0.15 degrees C, whereas trunk temperature was increased by 1.47 +/- 0.50 degrees C, and thigh temperature by 2.69 +/- 0.64 degrees C. Oxygen uptake increased 14-24% both before and during the exercise test in the stress experiment. During the course slightly lower rectal temperature levels were seen during the exercise test, whereas skin temperatures were significantly increased. Since the cadets' heat production and loss appeared to be increased and core temperature reduced, it is possible that we have observed a lowered set-point for core temperature.