Europe's Social Sauna Boom: What the Science Actually Says

This article is general information, not medical advice. If you have a heart condition, low or high blood pressure, or are pregnant, check with a doctor before using a sauna or cold plunge.

Short answer: The social sauna boom is a pleasant, mostly low-risk habit, but the health claims around it are running ahead of the evidence. Regular sauna use is linked to better heart health in long-running Finnish research, and a warm, phone-free hour with friends has obvious benefits for stress. But the evidence is observational, and the cold plunge half of "contrast therapy" is much less proven than its fans suggest. Verdict: Too Soon to Tell.

Walk along a harbour in Copenhagen, a riverside in London or a beach in Brighton and you may well pass a wood-fired sauna cabin with a queue of people in dressing gowns. Sauna culture, long a Nordic and German staple, has become one of Europe's most visible wellness trends. The UK, in particular, has gone from few public saunas to a thriving scene in a few years.

How Big Is the Boom?

• According to the British Sauna Society, as reported by Fast Company in March 2025, the number of public sauna sites in the UK jumped from 45 in 2023 to 147 in 2025.
• Market research group Grand View Research, cited by Euronews, projects the UK will lead Europe in sauna market revenue by 2033.
• The benchmark remains Finland, where Euronews reports there is roughly one sauna for every two people.

What's new isn't the sauna itself; it's the format. The new wave is social: shared cabins, DJ nights, aufguss rituals with music and scent, cold-water dips in the sea or a river, and sessions you book like a gym class. For some people it has become an alternative to meeting friends at a pub.

What's Actually Real Here

The most cited evidence comes from Finland. A study led by Jari Laukkanen, published in JAMA Internal Medicine in 2015, followed 2,315 middle-aged men in eastern Finland for a median of about 20.7 years. Compared with men who used a sauna once a week:

• those using it 2 to 3 times a week had a 22% lower risk of sudden cardiac death;
• those using it 4 to 7 times a week had a 63% lower risk of sudden cardiac death, 50% lower risk of fatal cardiovascular disease, and 40% lower all-cause mortality.

Those are striking numbers. Harvard Health notes that sauna heat raises the pulse by 30% or more, so there is a plausible link to the cardiovascular system. The study also reported that longer sessions (over 19 minutes versus under 11) were associated with a lower risk of sudden cardiac death, though that is not a reason to push past the comfort and safety limits below.

Where the Hype Outruns the Reality

It's observational. The Finnish study found an association, not proof that sauna causes the benefit. The researchers said further studies were needed to establish the mechanism, and the journal's editor noted it is unclear whether any benefit comes from the heat, relaxation, lifestyle or the social side of sauna culture. Men who sauna four times a week may differ in lots of ways: more free time, less stress, different jobs, closer social ties.

It's one population, and a small top group. The men were middle-aged Finns first examined between 1984 and 1989, which is not the same as a 28-year-old in Manchester doing a monthly session. Only 201 of the 2,315 men were in the highest-frequency group (four to seven sessions a week), and that is where the biggest effects were seen. That is a lot more than a weekly or monthly social session.

The cold plunge is a different story. Much of the new sauna culture pairs heat with a cold dip. Heather Massey, an expert in extreme environments at the University of Portsmouth, told Euronews that cold water triggers a gasp, rapid breathing and a rise in heart rate and blood pressure, and that "we just don't have that evidence" on what the benefits could be. She also stressed that social and environmental factors may be part of why people feel good afterwards. Some of the good feeling may come from being outdoors with like-minded people rather than the cold itself.

The Underrated Benefit: the "Social" Part

Here's where the hype genuinely lands. A sauna session is an hour without phones, in company, doing something that feels restorative. Britain's workplace health and safety regulator reported record levels of work-related stress in 2024 to 2025, with nearly a million workers affected by stress, depression or anxiety, according to Euronews, so a restful hour out has value. We made a similar point in our look at digital minimalism: the best "wellness" often looks a lot like rest and real-world connection. And if better sleep is your goal, a warm evening session may fit alongside the habits in our sleepmaxxing guide.

How to Do It Safely

1. Hydrate afterwards (Harvard Health suggests a few glasses of cool water) and skip alcohol before and after.
2. Keep sessions short at first. Harvard Health advises staying no longer than 15 to 20 minutes, and leaving if you feel unwell.
3. Enter cold water gradually and never alone. The RNLI advises walking in slowly, waiting until your breathing is under control before swimming, and going with a buddy or group; it says anything below 15C counts as cold water and the initial shock typically subsides within a minute.
4. Check with a doctor if you have heart problems, blood pressure issues, or are pregnant. Harvard Health says people with uncontrolled high blood pressure or heart disease should check first, and the RNLI says the same for people with cardiac or other underlying conditions considering cold-water swimming.
5. Leave if you feel dizzy. Heat and cold are both stressors; the aim is relaxation, not endurance.

FAQ

Is sauna good for your heart?

Long-term Finnish research links frequent sauna use with lower cardiovascular death rates, but it's observational. Sauna is a reasonable part of a healthy lifestyle for many people, not a replacement for exercise or medical care.

How often should you use a sauna for health benefits?

The strongest associations in the Finnish study were at 4 to 7 sessions per week. Two to three sessions a week was also linked to lower risk, but to a smaller degree. This is an association, not a prescription.

Do cold plunges after sauna have proven benefits?

Not strongly. An exercise physiologist told Euronews the evidence on the benefits is lacking, and the initial cold shock carries real risks for some people.

Why are social saunas so popular in Europe right now?

They combine wellness, socialising and outdoor time in a format that feels different from a gym or a pub, and the number of public saunas in the UK has grown quickly, according to the British Sauna Society.

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Hype-o-meter: Too Soon to Tell

The social sauna trend delivers something real: a relaxing, sociable ritual, and regular heat exposure is associated with better outcomes in Finnish research. But that evidence is observational and from one population, and the cold plunge half of the ritual is far less proven than Instagram suggests. Enjoy it as a pleasant habit, not a proven health intervention.

Sources

• Euronews Health: Saunas surge in popularity in Britain, but are the benefits proven?
• Fast Company: Communal saunas are on the rise in the UK
• JAMA Internal Medicine: Association between sauna bathing and fatal cardiovascular and all-cause mortality events
• ScienceDaily: Sauna use associated with reduced risk of cardiac, all-cause mortality
• Harvard Health: Sauna health benefits, are saunas healthy or harmful?
• RNLI: Essential safety advice for cold water dippers