Bath safety in Japanese winters: 7,776 bathtub deaths a year, 41°C water and 10 minutes max

Many homes in Japan are cold in winter outside the living room, and a hot soak in the bath is a daily ritual. The combination is risky. According to Japan's Consumer Affairs Agency (CAA), citing national vital statistics, 7,776 people died in 2024 from drowning in or falling into a bathtub, and 7,363 of them, about 95%, were 65 or older. The Government of Japan's public relations office says these accidents happen most from November to April. We could not find official English-language guidance on this from Japanese agencies, so the advice below is our translation of the Japanese sources.

Why baths are dangerous in winter

The CAA lists two main causes: sudden swings in blood pressure from moving between a warm room and a cold changing room or bathroom, and loss of consciousness from body temperature rising during a long soak in hot water. The government office notes that 10 minutes in 42°C water can raise body temperature to nearly 38°C, and that older people can faint from low blood pressure after meals. In Japan, the effect of these temperature changes is popularly called "heat shock."

The CAA also notes that deaths related to bathing are hard to count, because death certificates may record them as illness rather than drowning.

Before the bath (CAA)

• Warm the changing room and bathroom first. The government office suggests filling the tub from the shower to warm the air.
• Avoid bathing right after a meal, after drinking alcohol, or after taking medicine.
• Tell someone in the household before you go in. Family members should check on the bather from time to time.

In the bath (CAA)

• Keep the water at 41°C or below and soak for no more than 10 minutes.
• Do not stand up suddenly from the tub.
• If you start to feel faint, pull the plug before you lose consciousness.

Cold rooms

A survey by Japan's Ministry of Land, Infrastructure, Transport and Tourism found average winter temperatures of 16.7°C in living rooms, 12.6°C in bedrooms at night and 12.8°C in changing rooms. Homes where the living room or changing room was below 18°C were significantly more likely to have residents taking hot baths, which are considered higher risk. A small heater in the changing room can help (our suggestion); see "Space heater and kerosene heater safety."

If you find someone collapsed in the bath

The Government of Japan's public relations office gives these steps:

1. Pull the plug. Shout for help.
2. Lift the person out if you can. If you cannot, keep them from sinking, for example by resting their upper body on the tub cover.
3. Call an ambulance right away (119 in Japan).
4. Check for response and breathing, and if needed give 30 chest compressions and 2 rescue breaths, repeating.

A CPR class makes these steps much easier to carry out; see "Finding a CPR and first aid class."

If you are visiting or living in Japan (our suggestions)

• At a ryokan or public bath, take it slowly: rinse with warm water first, and get out if you feel dizzy.
• Do not soak after drinking, and do not stay in long when the water is very hot.
• If you have older relatives in Japan, agree on a quick call or message before and after bathing in winter.

For cold-related illness, see "Hypothermia and frostbite." A Japanese version is available: "冬の入浴事故（ヒートショック）を防ぐ" (in Japanese).