In this study, a subjective experiment was conducted in a climatic chamber to investigatethe effect of moderately hot environment on performance, fatigue, and especially the relationship between performance and fatigue. The climatic chamber was conditioned at operative temperature of 25°C (insulation value of 0.96clo), 28°C (insulation value of 0.96clo), and 28°C (insulation value of 0.61clo). Fourteen subjects were exposed in the environment for six hours. In this experiment subjects' performance at 28°C condition was lower than at 25°C condition, while they felt fatigue more strongly at 28°C condition than at 25°C condition. Besides, correlation between personal rates of complaints of fatigue and performance in z-score was observed with correlation coefficient of -0.72. From the linear regression model, increase in 10% of fatigue corresponded to the decrement in z-score by 0.083point.
