抄録
To investigate the effects of heat and exercise on firefighters wearing anti-fire coat, following measurements were made using five healthy untrained male subjects at rest and during exercise in a hot environment. The physiological parameters were loss of weight, axillary temperature, respiratory rate, ventilation, oxygen consumtion, carbon dioxide output, blood pressure, heart rate. The hematological parameters were red blood cell counts, white blood cell counts, and their differential. The blood biochemical parameters were osmolarity, Na, K, Cl, total protein, total cholesterol, free fatty acids, glucose, lactate, pyruvate, CPK, CPK isozyme, LDH, GOT, aldolase, creatinine, creatine, myoglobin, and those for urine were osmolarity, Na, K, Cl, urea nitrogen, creatinine, creatine, myoglobin. Two separate experiments were conducted as follows: sitting for 30 minutes in climatic chamber at 25°C, 35°C, 45°C and 55°C respectively with the relative humidity at about 40% and during exercise in the chamber at 25°C and 50°C with the relative humidity at about 40% for 20 minutes, including 10 minutes exercise with a bicycle ergometer at 600kpm/min followed by 10 minutes rest. Serum and urinary myoglobin were assayed by the radioimmunoassay method.
The degree of weight loss and increase in heart rate and serum enzyme activities were more significant when the subjects wore the anti-fire coat than when they were naked. GOT, LDH, CPK and serum myoglobin significantly increased after exercise at 50°C, but not after exercise at 25°C or at rest in 50°C temperatures. The results thus indicate that the effects of the combination of heat and exercise were greater than the sum of their individual effects.
It was concluded that heat stagnation must be taken into consideration, given the work condition and anti-fire coat worn by firefighters.
