ABSTRACT
A person regulates body temperature by outside and inside heat from change of environmental temperature. One of the inside heats includes drinking water. However, the effect of drinking water temperature on body temperature is not clear. The purpose of this study was to examine how water temperature influences the change in body temperature. The study participant were 13 men (average age, 21.3 ± 0.8 years), and they drank water at 3°C, room temperature, and 60°C; in addition, one more task was not to drink water. We measured tympanic temperature using a thermometer, skin blood flow using a laser Doppler flow meter, and sweating rate using the capsule ventilation method. The mean skin temperature was measured at seven body points with a thermistor and calculated. Tympanic temperature of drinking water at 3°C and 60°C was significantly in comparison with other conditions. As for skin blood flow between water temperature at 60°C and 3°C, sweating rate between water temperature at 60°Cand other conditions, and mean skin temperature between water temperature at 3°C and other conditions significant differences were recognized. It is thought that the response to early change to drinking water at different temperatures is by responses of thermo-receptors and subsequently by the thermal energy of the drinking water.
ABSTRACT
A person regulates body temperature by outside and inside heat from change of environmental temperature. One of the inside heats includes drinking water. However, the effect of drinking water temperature on body temperature is not clear. The purpose of this study was to examine how water temperature influences the change in body temperature. The study participant were 13 men (average age, 21.3 ± 0.8 years), and they drank water at 3°C, room temperature, and 60°C; in addition, one more task was not to drink water. We measured tympanic temperature using a thermometer, skin blood flow using a laser Doppler flow meter, and sweating rate using the capsule ventilation method. The mean skin temperature was measured at seven body points with a thermistor and calculated. Tympanic temperature of drinking water at 3°C and 60°C was significantly in comparison with other conditions. As for skin blood flow between water temperature at 60°C and 3°C, sweating rate between water temperature at 60°Cand other conditions, and mean skin temperature between water temperature at 3°C and other conditions significant differences were recognized. It is thought that the response to early change to drinking water at different temperatures is by responses of thermo-receptors and subsequently by the thermal energy of the drinking water.
ABSTRACT
Sensory estimates of thermal sensation of exercising unclothed five healthy male subjects have been compared with the associated thermo-physiological responses at various ambient temperatures.<BR>The subjects were exercising at approximately 50% of their maximal oxygen intake 30 minutes in a handmade wind tunnel. Three levels of ambient air temperatures were used at about 20°C, 25°C, and 30°C. Relative humidity was always maintained at about 60%, and the air movement was kept constant at 0.1 m/sec.<BR>Physiological measurements were thermal sensation, skin temperatures (22 points), rectal temperature, local sweating rate and total sweating rate.<BR>The relationship between rectal temperature and mean skin temperature and the estimate of thermal sensation was described by a summation model, where the thermal sensation was linearly related to the rectal temperature and the higher levels of mean skin temperature shifted the former relation to the higher deretion.<BR>The subjective estimate of thermal sensation (Sense) during exercise has been described as a summation of thermal signals from the core (Tr : rectal temperature) and the skin (Ts ; mean skin temperature) as follows ;<BR>Sense=2.21 Tr+0.29 Ts-84.81 (r=0.869, p<0.001)<BR>Further, the linear thermal sensation-rectal temperature relationship was dependent on ambient air temperature during exercise.<BR>Increasing the maximal oxygen intake decreased the gain of the thermal sensationrectal temperature relationship at only 30°C air temperature.<BR>It was difficult to estimate the local sweating rate by the degree of thermal sensation during exercise.