Effects of Room Temperature on Physiological and Subjective Responses during Whole-body Bathing, Half-body Bathing and Showering.

Abstract

The effects of bathroom thermal conditions on physiological and subjective responses were evaluated before, during, and after whole-body bath (W-bath), halfbody bath (H-bath) and showering. The air temperature of the dressing room and bathroom was controlled at 10°C, 17.5°C, and 25°°C. Eight healthy males bathed for 10 min under nine conditions on separate days. The water temperature of the bathtub and shower was controlled at 40°C and 41°C, respectively. Rectal temperature (Tre), mean skin temperature (T sk), blood pressure (BP), heart rate (HR), body weight loss and blood characteristics (hematocrit: Hct, hemoglobin: Hb) were evaluated. Also, thermal sensation (TS), thermal comfort (TC) and thermal acceptability (TA) were recorded.BP decreased rapidly during W-bath and H-bath compared to showering. HR during W-bath was significantly higher than for H-bath and showering (pϽ0.01). The double products due to W-bath during bathing were also greater than for H-bath and showering (pϽ0.05). There were no distinct differences in Hct and Hb among the nine conditions. However, significant differences in body weight loss were observed among the bathing methods: W-bathϾH-bathϾshowering (pϽ0.001). W-bath showed the largest increase in Tre and T sk, followed by H-bath, and showering. Significant differences in Tre after bathing among the room temperatures were found only at H-bath. The changes in Tre after bathing for H-bath at 25°C were similar to those for W-bath at 17.5°C and 10°°C. TS and TC after bathing significantly differed for the three bathing methods at 17.5°C and 10°C (TS: pϽ0.01 TC: pϽ0.001). Especially, for showering, the largest number of subjects felt "cold" and "uncomfortable". Even though all of the subjects could accept the 10°C condition after W-bath, such conditions were intolerable to half of them after showering.These results suggested that the physiological strains during H-bath and showering were smaller than during Wbath. However, colder room temperatures made it more difficult to retain body warmth after H-bath and created thermal discomfort after showering. It is particularly important for H-bath and showering to maintain an acceptable temperature in the dressing room and bathroom, in order to bathe comfortably and ensure warmth.

Risk factors of sudden death in the Japanese hot bath in the senior population

“…Typically, bathers leave the cool or cold environment (especially in winter) of the dressing room and immerse themselves deeply in hot water (40-43 8C) where they sit with the water up to their shoulders. Japanese researchers have long suspected that this style of bathing may have an influence on the cardiovascular system and hemodynamics [3][4][5][6][7][8]. Despite considerable research into this bathing style, it is still unclear what actually triggers a lapse in consciousness or sudden death in the elderly during bathing.…”

Effects of Room Temperature on Physiological and Subjective Responses to Bathing in the Elderly

“…These two differences might cause the large number of accidental deaths due to bathing in winter among the elderly in Japan. Although effects of bathing in hotter water in deep bathtubs on physiological and subjective responses have been reported on both the young Hashiguchi et at., 2002) and the elderly (Nagasawa et al, 2001;Chishaki et al, 2005: Asakawa et al, 2006, the effects of room temperature on these responses before, during and after bathing have been reported only for the young (Kanda et al, 1996;Hashiguchi et al, 2002).…”

“…Several studies (Hashiguchi et al, 2002;Yamazaki R., 2007) reported that the physiological strains during half-body bathing and bathing in cooler water are less than whole-body bathing and hotter water immersion. However, colder room temperatures made it more difficult to retain body warmth during and after half-body bathing and cooler water immersion.…”

“…Since cold exposure and large temperature variations cause physiological burdens and serious health complications, the reason for these accidental deaths in bathtubs might be cold exposure before, during and after bathing, and bathing in very hot water. Nevertheless, although the effects of room temperature on thermal responses for the young during and after hot bathing have been studied in various laboratories (Kanda et al, 1996;Hashiguchi et al, 2002), the number of studies of the elderly is limited. Therefore, though there are several safety guidelines for thermal conditions of the dressing room and bathroom; it is difficult to propose safety guidelines for the elderly.…”

Prediction of human thermophysiological responses during shower bathing

“…However, thus far the number of studies that have examined the thermophysiological response of the human body during bathing is limited, and most studies have used experimental approaches. Hashiguchi et al (2002), Tochihara (1999), and Ohnaka et al (1995) evaluated the effect of room temperature during and after bathing and the method of bathing (including immersion and shower bathing) on the thermophysiological response. Chiba et al (2005) clarified the cause of death and the risk factors that are related to sudden death in the Japanese senior population while bathing in a Japanese style "hot bath.…”