“Heat Shock” a Factor in Bathtub Drowning Deaths in Japan

Government statistics in Japan show that there were 8,993 drowning deaths in 2023. Almost 80% (6,909 deaths) occurred in a bathtub at home or elsewhere, with around 90% of those cases involving seniors aged 65 or over.

With the graying of Japan’s population, the number of seniors who drown in a bathtub has been gradually increasing. In contrast, deaths of seniors in traffic accidents have waned thanks to stricter penalties for hazardous driving and advances in preventative safety technologies such as collision mitigation braking systems. In 2023, nearly three times as many seniors died from drowning in a bathtub than from a traffic accident, at 6,073 deaths as compared to 2,116. As much if not more care needs to be taken at home than on the road.

Deaths while bathing among seniors are more frequent during the winter months in particular. This is due to the so-called “heat shock” effect caused by fluctuations in temperature, such as when a person goes from a warm living room to a cold bathroom. These can lead to a spike or fall in blood pressure, which may cause a heart attack or stroke.

The Consumer Affairs Agency cautions against taking a bath immediately after eating or drinking, and suggests that a changing room or bathroom should be heated prior to a bath to prevent heat shock.

Caution should also be exercised in the case of saunas, which have become popular among men and women of all ages in recent years. Because their blood vessels are more rigid than those of young people, seniors are at greater risk of suffering a myocardial infarction or cerebral hemorrhage from the sudden temperature change between a sweltering sauna and a cold bath.

Based on weather forecasts, the Japan Weather Association and Tokyo Gas publish a “heat shock forecast” on a website from October to March.

(Originally published in Japanese. Banner photo © Pixta.)