DISCREPANCY BETWEEN THERMOMETRY AND CALORIMETRY DURING EXERCISE

During prolonged exercise in a hot and dry environment one may observe that a man seems to maintain a caloric equilibrium for about one hour. When the man dehydrates, however, a continuous rise in rectal temperature may be observed simultaneously. This discrepancy between calorimetry and thermometry was investigated by measuring calorimetrically the body heat storage during exercise. In a series of experiments work and heat load were kept constant throughout (M=7.5 kcal/min; 35°C; RH 15%), but the exposure time was increased in steps of 18 min up to 144 min. The heat storage did not alter between the 54th and the 108th min. In the same period the rectal temperature rose steadily. © 1969 Springer-Verlag.