Why sauna naked?

A tradition built around washing

Finnish sauna culture reaches back thousands of years. Before modern bathrooms, the sauna was a place to wash; it also accommodated births and important family rituals. In new settlements it was often among the first buildings erected. Its significance went well beyond keeping warm.

That history helps explain why nudity feels so ordinary in a Finnish sauna. Clothes are removed for washing, and the sauna is part of the same routine. Today the tradition continues in homes, lakeside cottages and public saunas, although clothing rules vary—especially in mixed public venues. InfoFinland: Finnish sauna history and customs.

In 2020, UNESCO inscribed sauna culture in Finland on its Representative List of the Intangible Cultural Heritage of Humanity. The recognition celebrates a living culture of skills, customs and shared experience, passed between generations. It is recognition of the tradition, rather than certification of a particular health claim. UNESCO: sauna culture in Finland.

Why leave the swimsuit outside?

The clearest case for a naked sauna is a combination of local hygiene practice and comfort. The Finnish Sauna Society explicitly excludes swimming costumes from its saunas for hygiene reasons and provides a seat cover. Helsinki’s municipal swimming-hall guidance likewise tells visitors to wash without swimwear and leave it in the washroom before entering the sauna; a towel can be worn instead. These are concrete operating practices, rather than a claim that every swimsuit is dangerous. Finnish Sauna Society rules; Helsinki swimwear guide.

Removing swimwear lets you wash the skin it covers directly. Going without also means no wet fabric, elastic or seams against your skin while you sit in the heat. That is a practical comfort benefit; how much it matters depends on the person and the clothing.

A naked sauna still calls for a clean towel or seat cover. Shower beforehand and keep a barrier between your body and the bench. The Jyväskylä region’s sauna guidance recommends a seat towel whether you sauna naked or in swimwear: nudity alone is not a hygiene measure. Sauna procedures and hygiene.

What does sauna actually do to the body?

Sauna heat produces measurable changes in circulation. In a study of 102 adults with at least one cardiovascular risk factor, a 30-minute sauna session was followed by a fall in average blood pressure from 137/82 to 130/75 mmHg, alongside a reduction in measured arterial stiffness. This was an acute experiment: it demonstrates a short-term response, not a prescription for treating high blood pressure. Laukkanen and colleagues, Journal of Human Hypertension, 2018.

Longer-term research is promising too. A Finnish study followed 2,315 men aged 42–60 at enrolment for a median of about 21 years. More frequent sauna use was associated with lower risks of fatal cardiovascular events and death from any cause. Because this was an observational study, it cannot establish that sauna caused the difference; other aspects of participants’ health and lifestyles may contribute. Its findings also cannot automatically be generalised to everyone. Laukkanen and colleagues, JAMA Internal Medicine, 2015.

A systematic review of regular dry-sauna research found encouraging results across several conditions, but also substantial variation in study quality and many small studies. Sauna has a credible research base; the strength of a particular claim still depends on the evidence behind it. Hussain and Cohen, systematic review, 2018.

Does being naked add a health benefit?

The cardiovascular studies above examined sauna exposure. They did not establish that removing a swimsuit produces an additional health benefit. Their findings support discussion of heat, circulation and regular sauna use—not a promise that naked sauna improves heart health more than sauna in swimwear.

The strongest reasons to choose a naked sauna remain specific and tangible: following a well-established Finnish custom, washing without clothing in the way, and enjoying the heat without a wet swimsuit. Those reasons stand on their own, without extra claims about detoxification, fat loss or disease prevention.

A good naked sauna starts before you enter

Choose a venue or session that explicitly welcomes nudity. Some allow it throughout, some only inside the sauna, and others at particular events. Shower, bring a clean towel and follow the house rules. Sauna should feel comfortable: take cooling breaks and leave if you feel unwell. If you have a medical condition that could affect your tolerance of heat, seek individual advice before using it. Finnish sauna guidance.

For a first visit, knowing the clothing policy is as useful as knowing the temperature. Find the right setting, and taking off your swimsuit can simply become part of the routine.

Sources reviewed 9 November 2026.