ABSTRACT

It is a common Japanese custom to enjoy a hot bathdaily and it is also well known that hot bathing has beenassociated with sudden death, especially in elders. Approximately13% of the sudden death cases in Japan occur during bathing.This number has been increasing with the aging of Japan’spopulation. One of the causes lies in the Japanese bathing style, inwhich the bath consists of a tub deep enough for the bather toimmerse the body up to the neck in very hot water when sitting,and in the fact that the temperature of bathrooms is quite low inwinter season. Therefore, it is an urgent problem to study thephysiological effects of hot bathing and to educate Japanesepeople on its safe ways. This article reviews the variable effectsof hot bath immersion on human bodies in order to introduce thesafe way of hot bathing. Yet the definite causes of those deathshave not been fully understood. Thus, we investigated the effectsof bathing on the elderly, especially regarding cardiopulmonaryfunctions. We studied 12 apparently healthy elderly volunteers(70±5yr). They bathed in different temperatures (41。C, 38。C)on separate days. In the 38。C bath immersion, none of thecardiopulmonary indices changed significantly. In contrast, the 41。C bath immersion significantly increased BR, PRP, and Ttymp,suggesting a higher bathing temperature may give more stress tothe cardiopulmonary system. Bathing in hot water affected elderlypeople with underlying diseases much more than healthy oryounger people.