Effects of heat stress on acclimatized and non-acclimatized glass workers: 1 Physiological changes

ABSTRACT

Forty-six healthy adult male workers in a glass industry were divided into three groups Group I comprised acclimatized workers exposed to a moderate heat load, mean 442.2 BTU/hr; Group II were acclimatized workers exposed to a mean heat load of 1922.4 BTU/hr; and Group III consisted of non-acclimatized workers exposed to a mean heat load of 427.4 BTU/hr. Oral temperature, body weight, pulse rate, respiratory rate, oxygen consumption and blood pressure were determined for each individual before work and 2 1/4 hours after exposure to heat loads. There was a significant increase in body temperature, pulse rate, respiratory rate and oxygen consumption in all three groups after exposure to heat. Also, the rate of increase in these parameters was dose dependent. Acclimatization seems to keep the rate of increase within physiological limits. There was a slight loss in body weight, more apparent in workers exposed to a high heat load. Systolic and diastolic blood pressures were affected neither by exposure to heat nor by previous acclimatization of the workers