Saunas Can Help the Body Adapt to Heat, but Not a Solution During Heat Waves

Illustration of the use of a sauna. Repeated exposure to heat can help the body adapt, but it is not a direct solution during heat waves. Photo: Pexels.

JAKARTA - Repeated exposure to heat through saunas or hot baths is considered to help the body adapt to high temperatures. However, experts warn that this is not a direct protection when the heat wave is underway.

The Guardian, quoted on Monday, August 10, said that more and more studies are examining whether heat training can help the body prepare for extreme temperatures. The study comes as parts of the UK are experiencing their fourth heatwave of the year and the UK Health Security Agency or UKHSA has issued a heat health warning.

Professor Jari Laukkanen, a cardiologist from the University of Eastern Finland, quoted by The Guardian, said repeated exposure to heat can gradually make the body more able to cope with high temperatures.

"This is well known in exercise physiology. Athletes deliberately expose themselves to repeated heat to increase tolerance before competing in hot environments," said Laukkanen.

According to Laukkanen, similar adaptations can also occur through passive heat exposure such as saunas or hot baths.

The body can start sweating faster and more efficiently, blood flow to the skin increases, the volume of plasma or the liquid part of the blood increases, and the load on the heart and blood vessels decreases when it is exposed to heat again.

"Regular exposure to heat can help the body regulate temperature more efficiently," said Laukkanen.

Dr Jessica Mee from the University of Worcester said people who are used to facing the heat are also more likely to better regulate their activities, drink more regularly, and recognize the signs of the body starting to overwhelm them.

However, the benefits do not apply equally to everyone.

Dr Heather Massey, an expert in extreme environments and physiology from the University of Portsmouth, said heat adaptation depends heavily on the body's ability to increase sweat production and blood flow to the skin.

People who are experiencing acute illness or fever, unstable angina, have just had a heart attack, or uncontrolled low blood pressure should avoid saunas or similar heat exposure until they receive medical examination or treatment.

Experts say hot workouts typically require about 40 to 60 minutes of exposure every day for at least four to six days.

The benefits of adaptation can last about a week. Training that is carried out for longer can produce effects that also last longer.

However, heat adaptation is not the same as protection from heat.

"The evidence that going to a sauna during a heatwave can protect against heat-related illness is still limited," Laukkanen said.

According to Laukkanen, the benefits are more likely to come from long-term adaptation through regular heat exposure, rather than using a sauna as a quick way to deal with very hot weather.

Mee also reminded that sauna or hot bath can actually increase the body's burden if it is done on a very hot day.

"Heat adaptation is a preparation strategy for the months with milder temperatures, not a way to cope with the hottest day of the year," he said.

According to Mee, the body on a very hot day is likely to have been facing sleep deprivation for several nights, dehydration, and a burden on the heart and blood vessels that continue to accumulate.

Adding a sauna or hot bath in such conditions means giving the body an additional heat load.

According to research cited by The Guardian, most of the testing was done in a laboratory or controlled environment. Temperature and exposure time were monitored, while participants were under surveillance.

"We don't know how safe or effective this method is when it is done on its own at home without supervision," Mee said.

According to Mee, the fastest risk that can arise is fainting.

Laukkanen stressed that regular exposure to heat does not replace basic steps during heat waves.

"Regular exposure to heat is no substitute for drinking enough, avoiding strenuous activity at the hottest times of the day, and looking after vulnerable people," he said.