Indoor temperature, productivity, and fatigue in office tasks

The current status of Japanese office buildings is taken as an example and the balance of environmental concerns and office productivity are discussed. To promote the effort for energy conservation, it is important to estimate the indoor environmental quality from the aspect of office workers' productivity. Our experiments on the effect of moderately high temperature on productivity are noted. They showed that the effects of thermal environment on task performance were contradictory among the task types. However, the subjects complained of the feeling of mental fatigue more, and more cerebral blood flow was required to maintain the same level of task performance in the hot condition than at a thermal neutral condition. For evaluating task performance, the cost of maintaining performance, namely, fatigue and mental effort, is important in evaluating and predicting productivity. For long periods of exposure, indoor air temperature has effects on workers' performance.