As the UK faces a series of heatwaves, experts are examining whether regular sauna use can enhance our resilience to soaring temperatures. While the sauna trend gains momentum, particularly during the sweltering summer months, researchers are advocating for a cautious approach. Recent studies suggest that heat training may offer significant benefits, but it’s essential to understand its limitations and safe practices.
The Rise of Heat Training
With the UK Health Security Agency (UKHSA) issuing multiple heat health alerts this summer, the conversation around heat acclimation has intensified. The country has witnessed unprecedented temperature records, prompting many to seek refuge in saunas as a potential remedy for the heat. As Nicola Pegues, head of operations at Community Sauna Baths, noted, initial hesitance for bookings has transformed into renewed interest. These facilities, featuring outdoor saunas and cold plunges, allow users to alternate between extremes, purportedly providing a refreshing experience.
Professor Jari Laukkanen, a cardiologist from the University of Eastern Finland, has conducted extensive research on the health benefits of regular heat exposure. He asserts that consistent sauna use can gradually enhance the body’s ability to cope with high temperatures. “This phenomenon is well recognised in sports physiology, where athletes utilise heat exposure to improve their tolerance for competition in hot environments,” he explained. Notably, this adaptation includes increased sweating efficiency, improved blood circulation, and reduced cardiovascular strain during heat exposure.
Understanding the Physiological Changes
Research indicates that the physiological adaptations from heat exposure can significantly improve how the body manages temperature regulation. Laukkanen elaborates that regular sauna sessions may lead to enhanced plasma volume and more efficient skin blood flow, ultimately contributing to a more effective thermoregulatory response.
Dr Jessica Mee from the University of Worcester is currently investigating the effects of regular hot water immersion on heat responses. She highlights that individuals accustomed to heat often exhibit better pacing, consistent hydration, and an improved ability to recognise early warning signs of heat stress. However, she cautions that the benefits of heat acclimation are not universally accessible. “The body’s capacity to adapt hinges on its ability to increase sweating and blood flow to the skin,” she noted.
Safety Considerations and Limitations
Despite the potential advantages of heat training, there are notable safety concerns. Dr Heather Massey from the University of Portsmouth points out that individuals with certain medical conditions—such as acute illnesses, unstable angina, or uncontrolled low blood pressure—should avoid saunas until cleared by a medical professional.
Experts recommend that effective heat training requires 40 to 60 minutes of exposure daily for a minimum of four to six days, with benefits potentially lasting about a week. However, those seeking immediate relief during a heatwave must consider whether sauna use is suitable. Laukkanen warns that heat adaptation should not be confused with immediate heat protection. “The evidence currently suggests that sauna use does not safeguard against heat-related illnesses during heatwaves,” he stated. Instead, the benefits are derived from consistent exposure over time rather than acute sauna sessions during extreme heat.
Dr Mee reinforces this notion, stating, “Heat acclimation is primarily a preparatory strategy for milder months, not a remedy for the hottest days.” On particularly hot days, using a sauna can exacerbate thermal stress, especially when compounded by inadequate sleep and dehydration. “This creates a profile susceptible to heat-related illnesses,” she cautioned.
The Importance of Hydration and Public Health Advice
While saunas may emerge as a trendy response to heatwaves, experts stress that they cannot replace fundamental public health measures. Laukkanen emphasises the importance of staying hydrated, avoiding strenuous activities during peak heat, and ensuring vulnerable individuals receive adequate care.
“Regular heat exposure is no substitute for these essential precautions,” he advised. The immediate risks associated with unsupervised sauna use—such as fainting—underscore the need for caution. Dr Mee notes that many studies have been conducted in controlled settings, leaving unanswered questions about the safety of unsupervised sauna practices at home.
Why it Matters
As climate change continues to drive more frequent and intense heatwaves, understanding how to effectively prepare for and respond to extreme temperatures is crucial for public health. While heat training holds promise for enhancing our resilience, it is vital to approach it with care and to prioritise hydration and safety. Integrating public health recommendations with personal heat training practices will be essential in safeguarding health and well-being in an increasingly hot world.
