As heatwaves become more frequent and intense across Europe, researchers are exploring an unconventional strategy to help people cope: regular sauna sessions. A growing number of studies suggest that repeated exposure to high temperatures in a sauna may condition the human body to better withstand scorching outdoor heat, potentially reducing the health risks associated with extreme heat events.
The concept, sometimes called heat training or heat acclimatization, is not entirely new. It has long been used by athletes preparing for competitions in hot climates, but scientists are now asking whether it could benefit the general public as well. The research comes at a time when parts of the United Kingdom have experienced their fourth heatwave of the year, and western Europe has just recorded its hottest June on record. The UK Health Security Agency has issued heat health alerts across much of England, underscoring the urgency of finding ways to protect vulnerable populations.
The proposed mechanism involves repeated exposure to heat, which triggers physiological adaptations such as increased sweating efficiency, improved blood flow to the skin, and a lower core body temperature at rest. Over time, these changes can make the body more efficient at cooling itself, reducing the strain on the cardiovascular system during a heatwave. Saunas, which typically reach temperatures between 70 and 100 degrees Celsius, provide a controlled environment for such heat exposure.
While the sauna industry has boomed in recent years, with some venues marketing saunas as a way to beat the heat, experts caution that the practice is not without risks. The human body can struggle to regulate temperature in extreme heat, especially for older adults, young children, and people with underlying health conditions. Researchers emphasize that any heat training should be done gradually and with medical supervision, particularly for those who are not accustomed to high temperatures.
Several studies are now under way to determine the optimal frequency, duration, and temperature for heat training. Preliminary findings indicate that a few sessions per week, each lasting 10 to 15 minutes, may be sufficient to trigger beneficial adaptations. However, more research is needed to confirm the long-term effects and to establish guidelines for different age groups and health statuses.
The potential public health implications are significant. If sauna use can be shown to improve heat tolerance, it could offer a simple, low-cost intervention for communities most vulnerable to heatwaves. Some public health officials are already considering whether to include sauna recommendations in their heatwave preparedness plans, though they stress that common-sense measures — such as staying hydrated, seeking shade, and avoiding strenuous activity during peak heat — remain the first line of defense.
Critics of the idea point out that not everyone has access to a sauna, and that encouraging people to spend time in a hot room during a heatwave may seem counterintuitive. Researchers acknowledge these concerns but argue that sauna use in a controlled setting is different from prolonged exposure to outdoor heat, and that the benefits could outweigh the risks when done properly. They also note that other forms of heat acclimatization, such as taking hot baths or exercising in warm environments, may offer similar advantages.
The rise in sauna popularity has coincided with a broader interest in wellness practices that are believed to improve resilience to environmental stressors. Saunas are already associated with other health benefits, including improved cardiovascular function, reduced muscle soreness, and better sleep. The new research adds a potential heatwave adaptation benefit to that list, though scientists are careful not to overstate the findings until more data are available.
One challenge is that most of the existing research has been conducted on healthy young adults or athletes, so the effects on older populations — who are most at risk during heatwaves — remain less clear. Researchers are now designing studies specifically targeting elderly participants and people with chronic conditions such as heart disease or diabetes. Those groups are more likely to suffer heatstroke, dehydration, or worsening of existing illnesses during extreme temperature events.
As climate change continues to push global temperatures upward, the need for adaptive strategies becomes more pressing. The United Nations and the World Health Organization have warned that heatwaves are becoming more frequent, more intense, and longer-lasting, putting millions of people at risk. In this context, the sauna research represents a small but potentially valuable piece of the larger effort to help communities adapt to a warming world.
For now, health authorities advise that anyone considering sauna use as a heatwave preparation should start slowly, stay hydrated, and listen to their body. They also remind the public that saunas are not a substitute for the basic precautions recommended during heat alerts: keeping cool, drinking plenty of water, and checking on vulnerable neighbors and relatives.
The idea that a traditional practice like sauna bathing could offer a practical tool for modern climate adaptation is attracting attention from both scientists and policymakers. While the evidence is still emerging, the research suggests that with proper guidance, saunas could play a role in helping people endure the increasingly hot summers ahead.
