INFLUENCE OF HEAT-STRESS INDUCED DEHYDRATION ON MENTAL FUNCTIONS

The effect of primary dehydration of various levels (1, 2 and 3% body-weight deficits) on mental functions of different complexities were studied in eight heat-acclimatized subjects drawn from tropical regions of India. These subjects were also studied after a bout of exercise in hear under two conditions viz. Hot Dry (45.degree. C DB, 30% rh), and Hot Humid (39.degree. C DB, 60% rh) at 34.degree. C WBGT. No significant change in routine mental work was seen either under dehydration per se of any level or after subsequent exercise under heat when compared with the normal state. On the other hand, at 2 and 3% levels of primary dehydration a further reduction was noted in all the functions though it was not significant. Inter-variations in Hot Humid and Hot Dry conditions were not significant except for more pronounced reductions in the concentration component in Hot Humid conditions.