Effect of Moderately Hot Environment on Productivity and Fatigue Evaluated by Subjective Experiment of Long Time Exposure

In this study, a subjective experiment was conducted in a climatic chamber to clarify the effect of moderately hot environment on productivity, especially on the relationship between performance and fatigue. The climatic chamber was conditioned at operative temperature of 25.0C (insulation value of 0.93 clo), 28.0C (insulation value of 0.93 clo), and 28.0C (insulation value of 0.57 clo). Subjects were exposed in the environment for six hours. The performance at 28.0C condition was lower than at 25.0C condition. Performance decreased as the sessions proceeded, while the total rate of subjective symptoms of fatigue increased. Correlation between personal rates of complaints of fatigue and performance in Z-score was observed with correlation coefficient of -0.76. From the linear regression model, increase in 10% of fatigue corresponded to the decrement in standard number of correct answers by 1.7%. These results implied that thermal environment effected on performance and fatigue and subjects performed worse when they felt high level of fatigue.