Protecting Hair in a Hot Room

Does a hot room damage your hair?

Sauna heat alone is not known to damage hair structurally, but the dry air in a traditional sauna can pull moisture from the hair shaft, leaving it feeling brittle and flyaway. The Cleveland Clinic notes that traditional saunas typically run between 150 and 195 degrees Fahrenheit with humidity below 20 percent. Infrared saunas run cooler, around 110 to 135 degrees, but they still produce dry heat. Either way, a session in a hot room can dry out your hair if you do not take a few simple precautions.

Your hair is at its most vulnerable when it is wet, so the first line of defense is to enter with dry hair. This is a habit many long-time sauna users adopt, and it is especially useful if you have curly or delicate hair.

Why dry heat is harder on hair

In a traditional sauna, the air is dry and hot, which speeds up evaporation from the surface of your hair. The low humidity, often below 20 percent, means there is less moisture in the air to help your hair stay hydrated. That is why a quick rinse before you enter may not be the best idea, unless you plan to wear a cap.

Infrared saunas operate at lower air temperatures, but they still warm the room and your body. The lack of added humidity in most infrared cabins means your hair is exposed to the same drying effect, just at a lower temperature. Knowing which type of sauna you are using helps you adjust your routine. For more on the two types, see our guide on traditional vs. infrared.

Steam rooms are different. They fill the space with humid heat, which can keep your hair from drying out the same way a dry sauna does. However, the high humidity may make your hair limp or frizzy if you are prone to that. The MrSteam design guide notes that a steam shower delivers warm, moist heat, which is a very different environment from the dry air of a traditional sauna.

Drying your hair before you go in

Always enter the sauna with hair that is completely dry. Wet hair is more fragile and more likely to tangle or break when the hot air dries it quickly. Gently towel-dry or air-dry your hair before your session, and if you have been swimming or exercising, make sure your scalp is dry too.

If you do need to rinse off before using a sauna, tie your hair up or put on a cap before going in. This keeps the extra moisture off your skin and out of the hot room, and it also protects the wood benches from dripping water.

Braids and updos keep hair contained

Once your hair is dry, gather it into a loose braid, a bun, or a ponytail. This keeps strands away from your face and neck and prevents them from dragging on hot surfaces or getting tangled when you move around. A braid is often the best choice for longer hair because it stays secure even when you lean back or change positions.

For very long or heavy hair, consider a low bun at the nape of your neck. Avoid tight styles that pull on the scalp. Loose, comfortable positioning is better for circulation and helps you relax during your session.

Wearing a sauna cap

A sauna hat or cap is a classic piece of sauna gear for a reason. It covers your hair and scalp, and it also keeps the heat off your head so you can tolerate longer sessions. Traditional Finnish saunas often use felt hats made from wool, while cotton caps are lighter and easier to wash. Both work, and the choice comes down to personal preference. See our article on sauna hat purpose for more on why these are useful.

If you have already braided your hair, you can wear a cap over the braid to keep it tucked away. This adds a second layer of protection and is especially helpful in very dry or very hot rooms. When you are done, simply wash the cap the same way you wash your other sauna fabrics. For more on materials, read about felt vs. cotton caps.

If you use an infrared sauna, a lighter cotton cap is often more comfortable, because the room temperature is lower. You can check our guide on hats for infrared cabins for specific recommendations.

After your session: shampoo and condition

Finnleo recommends shampooing your hair after a sauna session to wash away sweat, salts, and any oils that have accumulated. A quick rinse or shower will close your pores and leave you feeling clean. Use a gentle shampoo followed by a conditioner to put moisture back into your hair, especially if you have color-treated hair or use heat styling tools.

The heat may open the cuticle, which is why a conditioner after a sauna can be especially beneficial. Let your hair air-dry after your session, and avoid brushing it while it is still damp to prevent breakage. If you use a sauna regularly, a weekly deep conditioning treatment can keep your hair soft and easy to manage.

You can also apply a leave-in conditioner or a few drops of hair oil to damp hair after your shower. This helps seal in moisture and adds shine without making your hair greasy.

What about steam rooms?

Steam rooms create a humid environment that is easier on your hair than a dry sauna. The moisture in the air can actually help your hair retain some hydration, but the constant condensation may weigh down fine hair or cause frizz. If you use a steam room often, follow the same principle of starting with dry hair, and wear a cap if you want to keep your hair off your face.

For a deeper comparison of steam rooms and saunas, read our article on steam room vs. sauna vs. steam shower.

What to pick for your hair type and routine

Questions

Can I wear a plastic shower cap in a sauna?

No, plastic does not let heat escape and can trap sweat, making your hair and scalp damp and hot. Use a breathable cotton or felt cap designed for saunas.

Should I wash my hair before or after a sauna?

It is better to enter with dry, clean hair. After your session, shampoo and condition to remove sweat and salts, as Finnleo advises.

How tight should a sauna cap be?

It should be snug but not tight, so it stays in place without pressing on your temples or leaving marks.

Can I use a hair mask or oil before going into the sauna?

It is not recommended, because hot air can activate oils and make your hair appear greasy, and some oils may get on the sauna wood. Apply treatments after you rinse.

Is it okay to go into a sauna with dyed hair?

Yes, but the heat can cause color to fade faster. Wear a cap to minimize exposure and use a color-protecting shampoo and conditioner after your session.

What should I do if my hair feels very dry after regular sauna use?

Increase the frequency of deep conditioning treatments and consider applying a lightweight hair oil before you enter, but only to the ends, and rinse it out after. You can also take a break from heat styling tools.