Glasses, Contacts, and Hearing Aids in Heat

Heat and Humidity in a Sauna

Traditional saunas typically operate between 150°F and 195°F, with humidity below 20%, according to the Cleveland Clinic. Infrared saunas use lower temperatures, usually 110°F to 135°F. This dry heat is different from a steam room, which uses high humidity. The type of sauna you choose affects how your accessories and body will respond.

Finnleo recommends staying in a sauna for about 10 to 20 minutes before taking a break to cool down. During that time, your body, and anything you wear, is exposed to significant heat. The heat is even more intense near the heater and upper benches. If you are planning to wear glasses, contacts, or a hearing aid, think about where you will sit and how long you plan to stay.

Understanding these conditions is the first step in deciding what to leave outside. For a deeper comparison of heat types, see our article on dry sauna vs wet sauna.

• Traditional sauna: 150 to 195°F, low humidity (Cleveland Clinic)
• Infrared sauna: 110 to 135°F (Cleveland Clinic)
• Recommended session length: 10 to 20 minutes (Finnleo)

Glasses: To Wear or Not to Wear?

At the higher end of a traditional sauna range, metal frames can absorb heat and feel uncomfortable against your skin. Plastic frames are less conductive but may still become warm, especially if you lean near a heater. If you need corrective lenses, consider removing them before you enter and placing them in a safe spot outside the hot room. Many saunas have hooks or small shelves just outside the door, but it is best to bring a hard case to protect them.

In an infrared sauna, the lower temperature may make wearing glasses more bearable. However, any moisture from sweat or steam can fog the lenses, so you might still prefer to take them off. Reading glasses are rarely needed in a dim sauna, so leaving them off is usually the simplest choice.

If you choose to keep glasses on, position yourself away from the heater and hot walls. Never place glasses on a hot bench or near the stones. Always follow the sauna's guidelines, as recommended by the Cleveland Clinic. For similar concerns with metal accessories, see our article on jewelry and metal in heat.

Contact Lenses in Dry Heat

Contact lenses sit directly on your eye, and the low humidity in a traditional sauna can speed up tear evaporation. This may lead to dryness and irritation, especially during a longer session. The Cleveland Clinic notes that traditional saunas have low humidity, which is a key factor. Even in an infrared sauna, the air can be dry because of the heating elements.

If you wear contacts, consider using lubricating eye drops before and after your sauna. Some people switch to glasses for the session, or simply remove the lenses and go without correction for 20 minutes. Pay attention to your comfort and leave the sauna if your eyes feel uncomfortable. It is also wise to wash your hands if you need to adjust the lenses, using clean hands avoids introducing bacteria.

In a steam room, where humidity is near saturation, contact lenses may absorb moisture from the air, but the high heat can still cause discomfort. The combination of heat and moisture can make lenses feel loose or tight. For more on the differences between dry and wet heat, see our guide on dry sauna vs wet sauna.

Hearing Aids and Other Electronics in Heat

Hearing aids are small electronic devices with batteries and microphones, and they are sensitive to both heat and moisture. Sitting in a sauna exposes them to temperatures that may exceed their operating range, potentially damaging components or reducing battery life. The moisture from sweat and steam can also corrode contacts. Because of this, it is wise to leave hearing aids in a dry, cool place before entering the sauna.

Other electronics, such as smartphones or music players, face similar risks. While some people listen to music through speakers, bringing a phone into the hot room is not recommended. The non-ionizing electromagnetic fields they emit are not known to cause direct harm, according to the NIEHS, but physical heat is a separate concern. A phone left on a bench can overheat and shut down, and the battery can degrade faster.

If you rely on a hearing aid for communication, let your sauna partner know you are removing it, and agree on signals or keep the session short. Also, consider using a waterproof case if you must keep it nearby. Always follow the manufacturer's guidance for operating temperatures. For more on electronic devices in hot rooms, see phones and electronics in heat.

• Leave hearing aids and phones in a dry, cool space outside the sauna.
• If you bring a device, use a sealed waterproof bag and avoid direct heat.
• Check the manufacturer's temperature range for any electronic device.

Safe Sauna Practices for Personal Items

The Cleveland Clinic stresses that saunas are safe when used within reason and that you should follow the guidelines of the sauna you are in. If you feel dizzy or uncomfortable, leave, cool off, and hydrate, as Finnleo advises. These practices apply to your body and to anything you bring inside.

Your personal comfort should guide decisions about eyewear and electronics. When in doubt, remove items that might be damaged by heat or moisture. It is also a good idea to bring a small bag or pouch to store these items safely in a locker or a dry shelf.

For a list of items that are generally not recommended in the hot room, see our article on what not to bring in. For session length guidance, see safe session limits from manuals.

What to pick for your use

Questions

Do glasses fog up in a sauna?

Yes, glasses can fog from sweat and humidity. In a traditional sauna, the low humidity might reduce fogging, but any moisture from your skin can still cause it. Removing them is often the easiest solution. If you must wear them, keep a microfiber cloth handy, but you may end up wiping them frequently.

Are contact lenses safe in an infrared sauna?

Infrared saunas run at lower temperatures, but dry still air can dry out lenses. Use lubricating drops and keep the session short. If you feel discomfort, remove the lenses. Some people prefer to switch to glasses for the session, especially if they plan to stay for more than 15 minutes.

Can I wear my hearing aids if I stay close to the door?

It's generally not recommended. Hearing aids contain sensitive electronics that can be damaged by heat and moisture. Even near the door, the exposure could be harmful. Store them in a protected case outside. If you need to hear a timer, use a vibrating watch or set a break reminder instead.

Should I take my glasses off before entering the sauna?

In most cases, yes. The high temperature can make metal frames hot, and you may risk dropping or losing them. Place them in a secure spot outside and retrieve them after cooling down. If you are in an infrared sauna and feel comfortable, you can keep them on, but be careful with sweat.

How long can I leave electronics near a sauna?

It's best to keep them out of the sauna entirely. Even outside the hot room, the area can be warm. Use a sealed container if you must bring them close, but the risk of damage remains. The high heat and humidity can warp or corrode components over time, so to be safe, store electronics in a cooler room.