Endurance of preheated men in exhausting work

Men worked themselves to exhaustion on a treadmill at 3.5 mph and a grade beginning at 10 percent and increasing by one percent per minute in a room at 46 degrees C. The men were first overheated by enclosure in a plastic bag or by immersion in a warm bath. Enough water was drunk to prevent dehydration. Effects of dehydration on endurance in exhausting work at 46 degrees C, reported previously, appear to be due mainly to overheating during the period of water restriction.