Interior of a traditional wood-lined sauna, illustrating the warm dry-heat environment that drives the UK norm around swimwear versus the European nude-norm tradition
Inside a wood-lined Finnish-style sauna. UK venues largely follow the swimwear convention; European cultures follow the nude one. Photo by HUUM | sauna heaters on Pexels.

What to Wear in a Sauna (UK Edition): The Honest Guide

UK saunas are not Finland or Germany. A clear guide to what to wear at wild saunas, gym saunas, hotel spas and home saunas — without the prescriptiveness.

If you have just looked up what to wear in a sauna because you are about to walk into one for the first time, the short answer for the UK in 2026 is: swimwear at almost every venue you are likely to visit, with one or two specific exceptions where the rule flips and a different etiquette applies. The fuller answer depends on the kind of sauna (wild beach sauna, gym, hotel spa, dedicated thermal venue, home sauna) and how much you care about authenticity versus convention. This guide walks through each setting honestly, including the awkward bits, without prescribing one true way to do it.

The UK convention versus the European one

The cultural baseline matters because it explains why UK saunas look different from the ones you may have seen in a Finnish summerhouse film or a German thermal spa. In Finland, saunas are part of the country's national identity and traditionally a place where clothing is removed; family saunas, friend saunas and even some workplace saunas operate on a textile-free convention with towels covering the bench, not the body. Germany, Austria, the Netherlands and Scandinavia mostly follow a similar pattern in dedicated spa venues — clothing is considered unhygienic for the wood and the heat, and most spas are explicitly nude-with-towel.

The UK has imported the sauna without the cultural framework. The default is treated as another room at the swimming pool — swimwear, modesty, a towel to sit on. This is partly because most UK saunas live inside leisure centres, gyms and hotel spas where the broader changing-room norm is swimwear; partly cultural conservatism about nudity in public; and partly the practical reality that mixed-gender, mixed-fitness-level public spaces in the UK have always trended towards 'cover up' rather than 'cover down'.

Neither convention is more correct. The honest UK answer is: follow the convention of the venue you are in, and don't worry about authenticity — the heat works the same either way.

Wild saunas: the UK's fastest-growing venue type

The UK wild sauna scene — beach saunas, lakeside barrel saunas, mobile horsebox saunas pulling up at coastal car parks — has exploded since 2022. These are the venues most readers find this guide before visiting, because the change-out logistics are less obvious than at a gym. The convention is almost universally swimwear plus a large towel, for three practical reasons:

You are doing the cold-water-dunk between rounds

The whole point of a beach or lakeside sauna is the contrast — hot session, plunge into cold sea / lake / cold tub, repeat. Swimwear is the obvious solution because you wear it on the cold side too. Coming out of the cold dip naked into a public beach is not the cultural register here.

The venue is partially or fully public

Wild saunas are usually pop-up structures on a beach, in a car park, or beside a lake — passersby can see in if the door is open, and the change-out area is often a small tent or a portaloo. Swimwear makes the public-private boundary manageable.

Mixed-group convention

Wild sauna bookings are almost always mixed-gender (couples, friend groups, family members of different generations). The UK default for a mixed-gender public-adjacent space is covered, and the venues design for that.

Many wild-sauna venues sell themselves on Instagram-friendly stylish swimwear photos, so do not overthink the aesthetics — anything you would wear at a UK lido or open-water swim is fine. A few venues offer dedicated nude-allowed sessions (clearly signposted, usually single-gender or pre-booked groups) but these are the exception; default to swimwear unless the venue's booking page explicitly says otherwise. The full venue listings sit at Wild Sauna UK: The Complete 2026 Guide and Beach Saunas UK 2026.

Gym, leisure-centre and hotel-spa saunas

The largest UK venue category — every council leisure centre, mid-range hotel spa, and gym chain operates a sauna where swimwear is the explicit house rule, almost always backed up by signage at the door. Practical points:

Swimwear — the same costume you'd wear in the pool

One-piece or two-piece for women, swim shorts or trunks for men. Avoid bikinis with metal underwires or clasps — the metal can get uncomfortably hot. Lycra/elastane swimwear handles 80–90°C heat without damage; cotton sportswear absorbs sweat and stays clammy.

Bring a large towel to sit on

Most UK gym and hotel saunas require this implicitly — and it's good hygiene regardless. The towel goes on the bench so sweat doesn't soak the wood. Bring a second smaller towel to wipe your face.

Flip-flops or pool slides for the walk to and from

Saunas in leisure centres are usually wet underfoot in the change-area corridor. Most venues do not allow shoes inside the sauna room itself — leave them at the door.

What NOT to wear

Cotton sportswear (gym kit) is discouraged at most venues — it traps sweat, and at extended sauna sessions wool/cotton garments can scorch or discolour from the heat. Jewellery (necklaces, earrings, watches) heats up and can burn skin. Make-up and heavy moisturisers melt and run; come bare-faced if you can.

Dedicated thermal-spa venues: the UK exception

A small but growing UK category — dedicated thermal-spa venues that consciously follow the German/Austrian textile-free convention. Thermae Bath Spa runs textile-free 'Twilight' sessions; some London-based saunas (Aire Ancient Baths Spa, Banya No. 1) and a handful of country-house spas (Eden Hot Tubs and similar) have textile-free zones or nude-allowed sessions clearly signposted on their websites. These are still a minority of UK venues, and the convention is usually textile-free with a large towel — you bring the towel onto the bench, wear it walking between rooms, and remove it for the actual sauna session.

If you are visiting one of these venues for the first time, check the booking page or call ahead. The websites are usually direct about which sessions are textile-free, mixed-gender, single-gender, and what the towel etiquette is. It is much less awkward to arrive prepared than to find out the rule at the changing-room door.

Home saunas: whatever you want

If the sauna is in your own house or garden, the UK convention does not apply — there is no etiquette beyond what you and your fellow users want. Most home-sauna owners use the sauna textile-free with a towel on the bench (the Finnish convention transfers cleanly to a private setting), but plenty of UK households use it in swimwear out of habit or shared-household preference.

Two practical points that do matter regardless of clothing:

Always sit on a towel

Sweat soaks into wood, and even kiln-dried sauna timber will discolour and develop odour over time if it absorbs body sweat directly. A large bath towel under the body and feet is the universally-recommended practice.

Take a quick shower first

Body lotion, sunscreen and aerosol deodorants react badly with hot wood — they smoke, leave residues, and degrade the wood finish. Five minutes under a lukewarm shower before the session is the right hygiene baseline.

If you are still researching a home unit, see Home Sauna Buying Guide UK 2026 for what actually matters across the price tiers.

Practical clothing and towel checklist

One swimsuit or pair of swim shorts

Lycra/elastane content, no metal hardware, dries quickly. Avoid pure cotton — it sags and stays damp.

One large bath towel for the bench

Sized to sit on plus a margin for spread. This is the most important item — every UK sauna setting requires or expects it.

One smaller towel for face and hair

Wiping sweat off the face during a session is comfort-critical; a small towel hanging round the neck is the standard pose.

Flip-flops or pool slides

For the walk to/from the sauna. Not worn inside.

A water bottle (some venues allow, some don't)

Hydration matters at 80–90°C. Many wild-sauna and home settings are fine with a water bottle inside; gym/spa saunas often restrict it to outside-the-room.

A change of dry underwear and clothes

You will be damp after the cold dip and the cool-down phase even if you towel off. A full change is worth the bag space.

Frequently asked questions

Can I just go in naked at a UK sauna if I want to?
Only at venues that explicitly allow it — and most UK venues do not. Going textile-free in a swimwear-required venue (gym, leisure centre, most hotel spas, every wild sauna we are aware of) breaches the house rule and will get you asked to leave. The exception is the small set of dedicated thermal-spa venues that signpost textile-free sessions; on those, follow the venue's specific etiquette.
Is cotton sportswear OK in a sauna?
Most venues discourage it. Cotton absorbs body sweat, becomes saturated, and stays clammy through the session. At sustained high temperatures cotton fibres can also scorch — small visible spots of darkening or holes from contact with metal jewellery. Lycra-content swimwear is the right baseline.
What about glasses, jewellery and watches?
Remove anything metal that touches the skin. Earrings, watches and necklaces heat to uncomfortable temperatures and can leave small burns at 80°C+. Glasses are usually fine — most UK saunas top out around 80–90°C which is below the temperature where glass-frame plastics deform — but they may steam up to the point where they are useless. Contact lenses are fine.
Should women wear a swimming costume or bikini?
Either is fine in UK venues. A bikini is more breathable and easier to dry; a one-piece is more conservative and avoids the metal-clasp issue with some bikini tops. Personal preference; both are entirely standard at every UK venue.
Can I wear a robe over swimwear in the sauna room?
Most venues prefer you do not — robes inside the sauna trap heat unevenly and shed lint as they dry-soak. The standard pattern is robe on for the walk from changing room to sauna, hang it on the hook outside the sauna door, sauna in swimwear plus bench-towel, robe back on for the cool-down or pool transfer.
Do I need different clothing for a wild sauna versus a gym sauna?
Not really. Swimwear that you would happily wear in a UK lido or for open-water swimming works for either. The main difference is logistics — wild saunas usually have a more rudimentary change-out area (a tent, a horsebox, a portaloo) so you may want to arrive already wearing your swimwear under your normal clothes.
Is there any UK sauna setting where I should NOT wear a towel?
No — the towel-on-bench rule is universal in the UK. Some textile-free venues remove the towel from the body but keep it on the bench. Sitting on bare wood is poor hygiene and most venues will ask you to use a towel either way.

The bottom line

The UK answer to 'what should I wear in a sauna' is, almost everywhere, swimwear plus a large towel. The handful of textile-free venues signpost themselves clearly on their websites, so unless you have actively booked one of those, plan for swimwear and a generous towel and you will fit the room. If you have your own sauna at home, the convention is whatever you and your household prefer — just always sit on a towel and shower first. The cultural difference between the UK and Finland or Germany is real but not problematic; saunas work the same either way, and nobody at a UK venue will judge you for following the local norm.

If you are new to the practice and not sure how long to stay in or how to structure the session, start with How to Sauna: A Complete Beginner's Guide for 2026.