Abstract
Seasonal variation of thermal conditions was investigated and it's heat stress to workers was discussed as follows.
At rush harvesting process, workers were exposed to scorching heat of the sun. In the process, the average value of WBGT-index for working hours was estimated to be 27.6°C (25.1°C-30.0°C), globe thermometer readings, 34.0°C (24.5°C-41.5°C) and Heat Stress Index, 58.7 (3.3-114.8) for males and 61.3 (-1.8-129.8) for females.
The amount of sweat in working hours was measured to be 4829±874 g for males, 4295±748g for females. And the rise in the concentration of serum protein, hemoglobin and hematocrit level was found after the work. This suggested that, although no case of heat stroke could be found, physiological functions of rush workers might be affected by hard physical work and heat stress through the process.
The workers were engaged in weaving in hot environment of 25-30°C dry-bulb thermometer from August to September in the working room. And at planting, they were in cold weather of 7-10°C in the paddy fields.
