A sauna hat keeps your head cooler than the air around it, so you can stay in the heat longer without your scalp and hair taking the damage. Heat rises. On the top bench, the air around your head is the hottest part of the room, and your head is the part of you least able to cope with it. A dense wool felt hat insulates against that, which is why sauna hats have been standard in Finland, Russia and the Baltics for generations.

What does a sauna hat actually do?

Three things:

• Keeps your head cool. Dense wool felt is a poor conductor of heat. It slows the transfer of hot air to your scalp, so your head stays closer to a comfortable temperature than the air in the room.
• Protects your hair. Repeated high heat and steam strips moisture from hair, leaving it dry, brittle and straw-like over time. A hat is a physical barrier between your hair and the heat.
• Extends your session. Most people leave the sauna because their head has had enough, not because their body has. Take the head out of the equation and you last longer.

Does a sauna hat protect your hair?

Yes — this is the reason most people buy one. Heat and steam open the hair's cuticle and draw moisture out. Do that several times a week and the cumulative effect is dryness, brittleness and breakage, particularly on longer or colour-treated hair. Covering your hair with dense wool felt keeps the worst of the heat off it.

We go into the detail in the complete guide to sauna and hair.

What should you wear in a sauna?

Less than you think, and nothing synthetic. The standard is:

• A wool felt hat — to keep your head cooler than the air and protect your hair.
• A cotton towel — to sit on. Every sauna expects this.
• Bare skin, or natural fibres only. Cotton or linen if you wear anything. Never polyester, nylon or elastane — synthetics trap heat against the skin and can hold odour.
• No metal. Jewellery, watches and glasses frames get hot enough to burn.

That's it. Anything else is either optional or working against you.

How thick should a sauna hat be?

Thickness is the single thing that determines whether a sauna hat works. Thin felt saturates with sweat and steam, and once it is wet it conducts heat rather than resisting it — which is exactly when you need it most.

Ours are hand-felted to roughly 6mm, several times thicker than the thin stitched hats sold as accessories. Dense enough to keep insulating through a full session, and it moulds to your head as you wear it.

More on what separates a working hat from a decorative one: why most sauna hats don't work.

Wool or felt — which is right?

It's not an either/or. Felt is what you get when wool fibres are matted and compressed together, so a good sauna hat is both: wool, felted. What matters is how it's made. Hand-felted wool produces a dense, seamless structure with no stitching to fail in the heat. Cut-and-sewn hats made from thin sheet material come apart and don't insulate.

Look for 100% wool, hand-felted, and enough thickness that the hat holds its own shape. Our complete buying guide walks through what to check before you buy.

Do you need a sauna hat in an infrared sauna?

Less so. Infrared cabins run much cooler than a traditional sauna and don't build the same layer of superheated air at head height. The hotter and steamier the room, the more a hat earns its place — in a traditional Finnish sauna or a banya, it's essential.

Frequently asked questions

Do you wear a sauna hat wet or dry?

Dry. A dry hat insulates; a wet one conducts heat straight to your scalp. Don't soak it before a session.

How do you wash a sauna hat?

Spot-clean only, and air dry. Never machine wash or soak wool felt — it will shrink and lose the density that makes it work. Full instructions are in our care guide.

Is a towel on your head as good as a hat?

No. A towel is thin, absorbs sweat quickly, and once damp it stops insulating. It also won't stay put. A towel is for sitting on.

Will a sauna hat make my head hotter?

No — it does the opposite. The felt keeps the room's heat out rather than trapping your body heat in.

How long can you stay in a sauna with a hat?

Longer than without one, but listen to your body rather than the clock. A hat removes the head discomfort that usually ends a session early; it doesn't remove the need to hydrate, cool down between rounds, and get out when you've had enough.

Does everyone wear them, or is it a Finnish thing?

Traditional in Finland, Russia and the Baltics, and now standard practice among serious sauna users everywhere. If you've been to a banya, you'll have seen them on every head in the room.

The short version

Your head taps out before your body does. A dense wool felt hat fixes that, and protects your hair while it's at it.

Browse our handcrafted wool sauna hats — free shipping on 2+ items.