Technical note. Comparison between estimated worn clothing insulation and required calculated clothing insulation in...

Six female and 33 male workers of the food industry (16-55 years), divided into three groups according to climatic conditions at the workplaces, were monitored during a typical shift. Fourteen subjects worked continuously in 0-7 degrees C, 18 in 13-15 degrees C and seven moved frequently between these climatic areas. Mean metabolic rates, heart rates, rectal temperatures and skin temperatures at the trunk and at the feet were similar between each of the three groups. Considerable differences between estimated clothing insulations worn and calculated required clothing insulations (IREQneutral) were statistically analyzed. The results suggest that--apart from a limited overestimation--this discrepancy is mainly related to the difference between time-adjusted averages of metabolic rates of the single activities and the respective daily minimum suggesting the need for an adequate weighting for the metabolic rates, particularly if workers are at least temporarily exposed to air temperatures of more than 7-13 degrees C.