Studies concerning the effects of the thermal environment on human productivity have been conducted usually either in the laboratory with young, healthy subjects who worked for short periods of time at artificial or military-type tasks (1) or in hot heavy industries. (2) Under laboratory conditions, both the type of work and the temperatures experienced by the subjects are controlled. Little evidence, except the anecdotal type, is available regarding the variation in individual productivity of ordinary men and women carrying out their normal work as the ambient temperature fluctuates on a day-to-day basis.

The present study was carried out to collect objective data on the productivity of a group of women working at their normal occupation as the temperature varied in a non-air-conditioned plant.