Sauna Hat Styles: Which One Actually Works?

Walk into any sauna these days and you'll probably spot three or four different hats on the top bench. The big felt bell that looks like it came out of a Finnish granny's hot press. A towel wrapped round someone's head like they've just stepped out of the shower. And, more and more, a plain wool beanie.

They all do roughly the same job. They don't all do it equally well, and they definitely don't all look the same doing it.

Quick bit of honesty before we start. I run The 90 Lifestyle, and we make one of these styles. I'll tell you which one and why. But I'll also tell you where the other styles win, because in a couple of cases they do.

Why wear a sauna hat at all?

Heat rises. In a traditional sauna the air around your head can be 20 to 30 degrees hotter than the air around your feet. Your scalp and hair take the brunt of it, which is usually why people get that dizzy, head-first overheating feeling and bail out before the rest of their body is ready to.

A sauna hat is insulation. Wool in particular slows down how quickly heat reaches your head, so your body can keep heating up while your head stays comfortable. It also keeps your hair from drying out and stops sweat running into your eyes. That's the whole job. Every style below is just a different take on it.

The main sauna hat styles

1. The traditional felt hat (the bell)

This is the one most people picture. Thick pressed wool felt, shaped into a bell or cone, sometimes with a little loop on top. It's been the standard in Finland for generations.

The good: felt is dense, so it insulates really well. If you're sitting in a proper wood-fired sauna at 100°C, a thick felt hat is hard to beat on pure heat protection.

The not so good: it's bulky, it sits high on your head, and it takes ages to dry. Some of them get a bit misshapen after a few months of sweaty sessions. And look, there's no nice way to say it. A lot of people feel like a garden gnome in one. One of our customers described the shape as "the flower bud design", which is about as kind as it gets.

2. The sauna beanie

 

A fitted knitted hat, usually wool, that sits close to your head like a normal beanie. This is the newer style, and it's the one you'll see more of in the likes of Dublin and London sauna spots.

The good: low profile, comfortable, and it stays put when you lie down on the bench. A good merino one handles heat and sweat well and dries fast. You can also just wear it outside afterwards, which you can't really say about a felt bell.

The not so good: a knit is lighter than thick felt, so at extreme temperatures it won't insulate quite as much as the heaviest felt hats. Cheap acrylic beanies are also out there being sold as "sauna hats". Avoid them. More on material below.

3. The bucket hat

Same felt or wool material as the bell, but shaped like a bucket hat with a short brim. It's a halfway house between tradition and something you'd wear in public.

The good: the brim shades your face a bit and can stop sweat running into your eyes. Decent insulation if it's proper felt.

The not so good: the brim hits the wall when you lean back, and it gets floppy once it's been soaked a few times.

4. Terry cloth and cotton towel hats

Basically a towel shaped into a turban or a cap. Popular in spas and with people who want to protect their hair more than anything.

The good: soft, absorbs sweat, easy to throw in the wash.

The not so good: cotton soaks up water and holds it. A wet towel on your head at 90°C is not insulation, it's a hot compress. It works in a cooler infrared sauna, less so in a traditional one.

5. Linen hats

Light and breathable, usually a simple cap or bucket shape.

The good: grand in warm weather and in infrared saunas, and they dry quickly.

The not so good: linen is too thin to insulate much, so in a hot traditional sauna you're not getting much of the benefit.

6. Novelty hats

Viking helmets, animal ears, hats with slogans stitched on. Usually cheap felt.

The good: great craic as a gift.

The not so good: you'll wear it twice.

What actually matters when you're picking one

The shape gets all the attention, but it's the least important part. Three things matter more.

Material. Wool, full stop, if you're using a traditional sauna. Wool insulates, it can hold a good bit of moisture without feeling soaked, and it doesn't hold smells the way synthetics do. Felt and merino are both wool, just made differently. Felt is pressed and dense. Merino is a finer fibre, knitted, so it's softer and lighter. Cotton and linen have their place, mainly in infrared saunas where it's a lot cooler. Acrylic and polyester blends have no place in a sauna at all.

Fit. A hat that slides off every time you lie down gets taken off and left on the bench. If it covers your crown and the tops of your ears and stays on, it'll do its job. If you have longer hair, check you can actually tuck it in.

Drying and care. You'll sweat into it every session. It needs to dry out between uses or it'll start to smell. Thin knits dry in a few hours. Thick felt can take a day or more. Either way, rinse it in cool water and air dry it. Don't put wool in the tumble dryer unless you want a hat for a toddler.

Why we went with a merino beanie

When I started The 90 Lifestyle, I'd been using saunas for years and had tried most of the hats above. The felt bells worked, but I never wanted to wear one. The towel wraps were fine until they got soaked. Nothing felt like it had been made for someone who does sauna three or four times a week and doesn't want to look like they're in fancy dress.

So we made the Sauna Beanie. It's merino wool, one size with a good bit of stretch, and it comes in black, grey and cream. It sits snug, covers your ears, stays on when you lie back, and dries quickly between sessions. It's unisex, and people with shoulder-length hair have told us it fits in no bother.

Is it the single warmest hat you can put on your head? No. If you're doing 100°C+ in a smoke sauna, a thick felt bell will insulate more. But for the way most people use saunas now, at the gym, a sauna club or a home sauna, a few times a week, it does the job properly and it's the one you'll actually keep wearing. We have customers wearing theirs around town all winter too.

Have a look at the Sauna Beanie here.

So which sauna hat style should you get?

If you do traditional Finnish-style saunas regularly and want something you'll actually wear, get a wool beanie. It's the best all-rounder.

If you mostly do very hot, old-school saunas and don't care how it looks, a thick felt bell hat will give you the most insulation.

If you mainly use an infrared sauna, heat is less of an issue. A beanie, linen or cotton hat will all be grand.

If hair protection is your main reason for wearing one, go for wool over cotton. It protects better and won't turn into a hot, wet towel halfway through.

Sauna hat FAQs

Can you wear a normal beanie in the sauna?

Only if it's 100% wool. Most high street beanies are acrylic or a poly blend, which traps heat against your head, holds sweat and ends up smelling. A proper sauna beanie is made from wool for that reason.

Felt or merino, which is better for a sauna hat?

Both are wool, so both work. Felt is thicker and insulates a bit more, but it's bulky and slow to dry. Merino is lighter, softer and dries faster. For regular use, most people find merino easier to live with.

Should you wet your sauna hat before going in?

Some people dampen a felt hat first to keep it cooler for the first few minutes. With a merino beanie you don't need to. Put it on dry and let it do its job.

How do you wash a wool sauna hat?

Most people don't but if you need to, rinse it in cool water after a session, squeeze it out gently and let it air dry. No hot washes and no tumble dryer.

Do sauna hats work in infrared saunas?

Yes, but they matter less. Infrared saunas run a lot cooler than traditional ones, so the hat is more about comfort and hair than heat protection.