Thermal limits for industrial workers.

259-264. The literature on relationships between man's comfort, efficiency, and physical well-being and the nature of his thermal working environment is diverse and highly specific. Industrial practice requires more general `concensus' data on which to base reasonable recommendations for the establishment of thermal environmental limits. A series of three such limits is proposed which provide protection of the workers' comfort, efficiency, and physiological safety. For sedentary workers it is suggested that in summer an upper limit of 21·8°C C.E.T. is advisable if not less than 80% of workers are to be free from discomfort. Against a similar criterion in winter a lower limit of 15·5°C C.E.T. is proposed. An extrapolation of data from laboratory to industrial work-places provides a suggested limit for efficiency at skilled tasks at 26·7°C C.E.T. Finally, a limit of environmental severity based upon an absence of severe physiological distress in 95% of exposed workers is proposed which varies with the age and physical fitness of the workers and the physical demands of the work they are called upon to perform.