The effects of thermal discomfort on task performance, fatigue and mental work load examined in a subjective experiment

A subjective experiment was conducted in a climate chamber to investigate the effects of thermal discomfort (feeling too warm) on the performance of office work. Twenty-seven Danish female subjects were exposed in a climate chamber to four conditions with different levels of thermal discomfort provided by a combination of operative temperature and amount of clothing. Thermal sensation votes towards the end of exposures were neutral, slightly warm, warm and very warm. More symptoms indicating mental fatigue were observed with increased thermal discomfort. The subjects reported that more effort was necessary when they felt thermally warm compared to conditions in which they felt thermally neutral and slightly warm. Performance of proof-reading, addition and text-typing tasks was not affected by thermal discomfort. This suggests that the subjects were able to maintain their performance but as a result they got more tired and the mental work load increased.