The effects of two different types of clothing on seasonal cold acclimation of thermophysiological responses

The work described in this paper investigated the effects of two types of clothing, leaving the legs covered or uncovered, on seasonal cold acclimation in women. Experiments were carried out to observe the different thermal physiological responses between two groups of subjects, who dressed themselves in kneelength skirts or trousers during the daytime for 3 months from September to November. It was found that rectal temperatures and heart rates in the subjects wearing skirts were shifted to lower levels when the season gradually became colder. The results suggest that the clothing type worn in daily life may play a potential role in seasonal cold acclimation of thermal physiological responses in man.     

A model of evaporation from the skin while wearing protective clothing

 A simple model was developed to describe the transport of water vapour from subjects working in hot environments while wearing chemical-protective clothing. The goal of the modelling was to obtain a better estimate of evaporative cooling of the subjects, as it was hypothesised that calculations of evaporative heat loss based on changes in dressed weight over-estimate the actual benefit experienced by the subjects. The model employed measured values of vapour pressure within the clothing ensemble to estimate the skin vapour pressure. The resistance of the clothing ensemble to water vapour transport was calculated from measurements of the physical properties of the materials in conjunction with estimates of the resistance of air layers between the clothing layers. The model predicts mean evaporation rates from the skin that are approximately 60% of those calculated from measured changes in dressed weight. Error analysis failed to account for the magnitude of this difference and possible explanations for the difference are advanced. A brief examination of the effect of wicking suggests that some of the difference results from a reduction of the resistance of the garment to water vapour due to wicking of liquid sweat through fabric layers. Received: 4 June 1997 / Accepted: 21 October 1997