Circulatory and biochemical effects of whole body hyperthermia

The physiological effects of whole body hyperthermia to 42 C° have been studied in 12 subjects. There was a sustained increase in the heart rate and an initial increase in the arterial and central venous pressures. Sweat and electrolyte losses were high. The serum bilirubin remained normal if the temperature did not exceed 41.8 C°. Above this temperature the serum enzymes lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase rose, as did the serum bilirubin. While the latter effect might be due to liver damage, it could also be related to thermal destruction of red cells. A leucocytosis develops during the hyperthermic state.