Physiological Responses and Thermal, Humidity, and Comfort Sensations in Wear Trials with Cotton and Polypropylene Vests

Abstract

Relations were studied between skin temperature of the back as well as temperature and humidity inside clothing, and subjective estimates of thermal, humidity, and comfort sensations in 5 subjects wearing cross-country ski dress. The 2-h wear trials were performed in a climatic chamber at −2°C and simulated the actual circumstances under which such a dress is worn by alternating periods of intensive walking (20 min) on a treadmill with periods of resting (5–10 min). Each subject participated in 4 trials wearing alternately one of the 4 experimental, double-layer vests (double-cotton, cotton-polypropylene with cotton layer next to skin, same combination with polypropylene layer next to skin, double-polypropylene). Skin temperature of the back was during the experiments systematically lower ( P<0.05) by about 1°C with the double-layer cotton vest than with the double-layer polypropylene vest. Since the physical parameters of the two fabrics were not identical, the findings cannot be definitely attributed to the inherently different properties of the fibers. No significant differences were found in the 4 experimental series either in other objective measurements (temperature and humidity of the microclimate, energy output, total amount of sweat, amount of sweat trapped in the vests) or in subjective estimates of thermal, humidity, and comfort sensations. Gradual increase of skin temperature as well as of temperature and humidity (sweating) of the microclimate was recorded during walking periods. When walking was interrupted by a pause, both the temperature and humidity rose steeply, due to the cessation of bellows ventilation of the clothing, and fell again when walking was resumed. The thermal and humidity sensations on the back reported after the turning-points of the intermittent activity showed opposite direction of changes than those of the recorded parameters— i.e., decrease during pauses and increase after walking was resumed. It is possible that the perception of local sensations was affected by superimposed, central perception of changes in the amount of heat delivered from muscles to the brain receptors. The sensations of comfort seemed to be affected mostly by perception of “warmth” when walking and “cold” when resting.

Impact of wet underwear on thermoregulatory responses and thermal comfort in the cold

“…Adler and Walsh (1984) observed, in a wann condition, that vapour diffusion was the major mechanism of moisture transport between two layers of fabric at low moisture levels, and that transport of water between two adjacent fabrics (wet and dry) only took place when they were held together under pressure and the moisture content of the wet fabric was considerable. Measured values of the moisture content in underwear even after heavy sweating represent less than ] 00% of the dry fabric weight (Vokac et al 1976). …”

“…Several investigators (Andreen et al 1953, Rodahl et al 1973, Vokac et al 1976, Holmer 1985, Nielsen and Endrusick 1988 have tried to demonstrate this during controlled laboratory conditions on test-subjects in a resting period following hard work. So far nobody has succeeded in demonstrating distinct differences in physiological responses due to different underwear-types during the resting period in the cold.…”

The effect of hyperhydration on physiological and perceived strain during treadmill exercise in personal protective equipment

“…Rating of perceived exertion was obtained with the OMNI RPE scale where exertional ratings ranged from 0, "extremely easy," to 10 "extremely hard" (Utter et al 2004). Comfort was assessed with a general (overall) comfort scale anchored by 1, "comfortable," and 4 "very uncomfortable" (Vokac et al 1976). Thermal burden was assessed with (1) the modiWed Gagge thermal sensation scale anchored by 1, "comfortable," and 5 "very hot" (Gagge et al 1969) and (2) a sweating sensation scale anchored by 0, "not at all," and 3 "heavily sweating."…”

Physiological significance of hydrophilic and hydrophobic textile materials during intermittent exercise in humans under the influence of warm ambient temperature with and without wind

“…However, because of their hydrophilic ®bre surface, they have an ability to transfer moisture. Vokac et al (1976) andHolme r (1985) have tried to study the physiological responses under the inuence of dierent materials of underwear during intermittent exercise, but they have not found any dierence. It is necessary for more data to be collected for a systematic understanding of the relationship between textile materials and physiological responses.…”