Abstract
Three healthy adults were exposed to high temperature (38°C, 40°C and 43°C) and high humidity (60%) environment for 90 minutes 3 times at 3 or 4 days' intervals in winter. The number of circulating eosinophils and 17-ketosteroid excretion in the urine were determined before, during and after each heat load. The following results were thus obtained.
1) Due to exposure to each heat load, circulating eosinophil count was found decreased without any connection with heat level, but, after repeated exposures, an increase in the basal level of circulating eosinophils was observed.
2) After repeated exposures to heat, an increase in the excretion of 17-ketosteroid during exposure to heat was noted, but a decrease in the total amounts of 24 hours' excretion was recognized with repetition of exposure to heat.
3) After each exposure to heat stress, a marked increase in the hemoglobin concentration was noted, but the basal level was found lowered with repetition of exposure to heat.
In view of the above, it may be concluded that pituitary adrenocortical function has been altered through exposures to heat stress, and that this alteration is connected with the acclimatization to such high temperature-humidity environment.
