During exercise in water children's body temperature are especially likely to be affected by a cold water environment because of their morphological characteristic. There is a lack of information about the recommended environmental condition for elementary school swimming classes based on scientific objective data. This study investigated multiple effects of the environmental condition, morphological characteristics, and swimwear condition on children's thermal sensation during an elementary school swimming class. The sixth-grade elementary school children (n=68) participated in a swimming class conducted in the outdoor pool eight times. They wore a normal swimsuit or a partial coverage wetsuit. During the swimming class, water temperature and ambient temperature were continuously measured. children's thermal sensation was asked at the poolside immediately after each swimming class. Multiple regression analysis was performed to make an estimation equation of children's thermal sensation. The equations contain three predictors of water temperature, swimwear condition, and their morphological characteristics. The result of standardized regression coefficients indicated that, water temperature was the greatest contributor to their thermal sensation, followed by the swimwear condition, and morphological characteristics. On the basis of the analysis, presumably the thermal effect of a partial coverage wetsuit was equivalent to the increase of water temperature by 2.1°C and it makes children feel warmer thermal sensation. Additionally, the thermally comfortable area was indicated as the relationship between water temperature and children's morphological characteristics for each swimwear condition.

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The purpose of this study was to investigate the effects of thermal environments in which the air temperature close to the floor is lower than the temperature close to the ceiling on physiological and subjective responses in the elderly. The temperatures around the upper and lower parts of the body were controlled independently using a climatic box placed in a climatic chamber. Sixteen healthy male subjects (8 elderly and 8 young) were exposed to four conditions involving various temperature differences between the upper (25°C) and lower (16, 19, 22, or 25°C) parts of their body. Although there was no significant difference in mean lower body skin temperature between the two age groups, the skin temperatures of the hand and fingers decreased more in the elderly at temperatures of 22°C and below. Systolic blood pressure significantly increased in low air temperature conditions in the elderly, but not in the young. Age differences in thermal sensation of the whole body and lower body thermal comfort were detected, and the perception of the vertical air temperature gradient was reduced in the elderly. These findings suggest that the skin temperatures of the fingers and hand decrease and blood pressure increases in the elderly in unequal thermal environments in which the air temperature close to the floor is lower than that in the upper part of the room, although their perception of the temperature difference is reduced. It is necessary to avoid air temperature depression in the lower part of the room to maintain thermal comfort and stabilize blood pressure in the elderly.

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Changes in heat loss after light-short exercise and unwarmed food intake were investigated using partitional calorimetry to test the hypothesis that heat loss following these treatments is due to sweat evaporation (E_sk). Four Japanese male subjects exercised at 30% of their maximum workload for 10 min and rested for 60 min. They ate 200 g almonds, drank 100 g green tea and rested for 120 min on different occasion. Rectal temperature, oxygen consumption, body weight, skin temperatures and local heat flow rates at seven sites on the skin surface were measured at 2-min intervals. The results demonstrated that the heat stored during exercise was dissipated by E_sk with a 16 min delay whereas the heat produced by diet induced thermogenesis was dissipated by E_sk without delay. Therefore, it was demonstrated that the supplemental heat loss pathway after both light-short exercise and unwarmed food intake was E_sk.

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