Japan’s cold winter brings heat shock health hazards due to temperature changes

blood pressure fluctuations

Dr. from Tokyo City University. Hayasaka Shinya specializes in research on baths and hot springs. Moving from a heated living room to a cold locker room or bathroom causes people’s blood vessels to contract, which suddenly raises blood pressure, he says.

Soaking in the bath causes blood vessels to dilate, which causes blood pressure to drop, which rises when the bather exits the tub and enters a cold room.

Large fluctuations in blood pressure can cause symptoms such as dizziness and nausea. They can also strain blood vessels and the heart, even leading to heart attacks and strokes.

Bathing deaths increase in winter

Although there are no statistics showing deaths from heat shock, this phenomenon likely explains the seasonal increase in bathing deaths.

Japan’s Consumer Affairs Agency says the number of people aged 65 and over who drowned while bathing nationwide in 2022 reached 5,824; This figure is 2.7 times the number of elderly people who died in traffic accidents in the same year.

The agency analyzed its data in 2019 and found that most fatal bathroom accidents occurred between November and April, peaking in January.

To save lives, the agency urges people to minimize temperature differences whenever possible, including heating locker rooms and bathrooms.

One man’s experience

Hamada Satoru, a 42-year-old office worker from Hacinohe City in Aomori Prefecture, suffered heat shock in early December two years ago.

Hamada says she bathes with her children. After being in the tub for about 20 minutes, she didn’t feel well, so she hurried out to get dressed.

He felt so dizzy and nauseous that he could not stand up, then lost consciousness and collapsed. He regained consciousness a few minutes later when his wife called out to him.

Hamada had never felt heat shock before this experience. It has since begun taking steps to minimize temperature fluctuations.

“I was lucky to have my family around to help me,” Hamada says. “But from my own experience I have realized that if I had been alone in a similar situation I could have died. I hope people realize they could be in danger and take due care.”

Hammam takes preventive steps

Myohouyu, a public bathhouse in Tokyo’s Toshima Ward, is taking steps to prevent heat shock.

Yanagisawa Yukihiko, the owner of the facility, says that elderly people living alone often go to public baths during the winter months because they are afraid of the bathrooms in their homes collapsing.

He says he keeps the temperature in the changing rooms at 25 degrees Celsius and keeps the door between the rooms and the bathroom open to reduce temperature differences.

Yanagisawa says he also replaced his bathroom tiles five years ago with a material that didn’t feel so cold. Hot water overflowing from the bathtub heats the tiles.

“I’m always thinking about how to make sure people can bathe safely,” he says. “I want people to be careful, for example, pour hot water on their feet and hands before getting in the tub.”

Young people are also at risk

Dr. In addition to the elderly, people with high blood pressure or heart disease are also at risk, Hayasaka says. Even teenagers need to be careful when taking long baths because smartphones that keep them in the tub for long periods of time can distract them.

He recommends keeping the temperature difference between rooms within 5 degrees Celsius and keeping the bathroom temperature around 40 degrees. He also recommends a safe bath time limit of about 10 minutes.

“If the weather suddenly gets cold, your body won’t have time to adjust, so you’re more likely to suffer heat shock,” he says. “Eliminating the temperature difference is the most important thing.”