Nearly 1000 black and white, male and female factory workers were exposed in single-sex groups of four, each group working a full shift and attending for 1 day only, to air temperatures of 6, 12, 18, 24°C (cold series) and 20, 26, 32, 38°C (hot series). All exposures were at low humidity. Clothing levels were fixed for the cold series and the hot series. The exposures took place in a mobile climate chamber on the factory site and the workers performed a series of tasks to simulate factory work. Significant effects of temperature were recorded and the implications for factory design are noted.

The relationship between finger skin temperature (FST) and performance was demonstrated with four manual dexterity tasks all of which were performed by black and white, male and female subjects. At air temperatures below 24°C the white subjects tended to have warmer FSTs than the black subjects; white subjects were also able to equal the performance of the black subjects at air temperatures as much as 6°C below that required by the black subjects.

An extended study of the effect of moderate thermal stress on the performance of tasks simulating aspects of industrial work has been under way since 1977. Factory workers were used as test subjects, each being exposed to a single test condition for a full shift in a mobile climate laboratory.