Promotion of Evaporative Heat Dissipation by Water-dispersed Cloth onFunctional Wear and Improvement of Thermal Comfort by UV Scattering

Abstract

Whole-body cooling is the most effective measure against hyperthermia in a hot environment, but it is important to predict and prevent such an excessive rise of body temperature. Thermal sensation and comfort are critical for prediction. Thermal comfort depends on the core temperature, but also on information from skin temperature receptors. Thus, the thermal sensation can be altered when the condition of the skin surface changes due to radiation {i.e., ultraviolet （UV） and infrared （IR） }, evaporative cooling （i.e., sweating）， or skin lotion （i.e., foundation or insect repellant spray, etc）．The purpose of this project was to propose a countermeasure against heat stress by utilizing unique clothing. In the laboratory experiment, we investigated the change in temperature sensation due to ultraviolet irradiation and the protective effect of clothing using artificial sunlight. As a practical study, we focused on the transpirational effect of spraying micro-mist over functional innerwear, and investigated the effect of spraying micro-mist on evaporative heat loss. In addition, we conducted a questionnaire survey involving university students, including university student athletes, about their awareness of heat stroke and how to deal with it. Thermal sensation was more sensitive one day after artificial sunlight exposure, but was preserved by UV-cut wear. Spraying micro-mist promoted evaporative heat loss, making it comfortable to watch sports in a hot environment.