抄録
A experiment was conducted in a climate chamber conditioned at operative temperature of 25.5℃, 28.5℃ or 31.5℃ to examine the effect of task load and thermal environment on productivity. The sixteen male subjects were assigned in each condition to work on three-digit multiplication task both at maximum and at normal speed for fifteen minutes. RTLX from NASA-TLX, and the task performance were significantly higher at the maximum speed but was not significantly different among the conditions. The cerebral blood flow in the 31.5℃ condition was significantly higher at the maximum than that at the normal speed. The cerebral blood flow and RTLX were both considered as the index of mental workload; however their sensitivity to indoor environmental stress can be different.