Humans under showers: thermal sensitivity, thermoneutral sensations, and comfort estimates

Thirty male subjects participated in four experiments under showers to explore the sensitivities to water temperature and to its slow or rapid fluctuations. After having set the water temperature, at constant flow rate, at either a thermoneutral or a preferred level, subjects were asked to detect thermal changes or to report their thermosensory and affective judgments associated with water temperature changes. Results of water temperature, skin temperature, and subjective estimates showed that skin temperature for thermally neutral sensation under a shower were very similar to those observed in air, and such a thermoneutral level produced no discomfort. Preferred water temperature was slightly warmer and led to slightly elevated skin temperatures, warmth, and pleasantness estimates. Skin sensitivity to water thermal changes was very acute during slow and even more acute during rapid thermal transients. The conclusions of the present study are of value in the production of appropriate equipment to provide thermal comfort to people taking showers.