Wearing a Smartwatch in a Sauna

Are there smartwatches that one can wear in a sauna or steam room? The short answer is definitely Yes there are smartwatch models that can bear the steamy sauna. It depends on the waterproof rating mostly but it makes sense also checking the manufacturer’s recommendations. Also, consider the temperature change in the Sauna.

Based on my research it would seem that Polar would be the brand to go with regarding sauna usage. Check the brand-specific sections at the end of the article.

What determines is the device safe for sauna

Finnish Sauna

A sauna is a room or building designed for experiencing heat sessions. Usually, the temperatures in a sauna can be around 80-90 °C and the steam is generated by pouring water on hot stones.

Since you have steam which is essentially water and heat the two things you should be looking at are the waterproof rating and the operating temperature rating.

Waterproof rating

Devices are usually rated with an ATM rating or a depth rating in meters. ATM is the Atmospheric pressure which tells you how effective a device is in withstanding the pressure until a specific depth. At sea level, the average Atmospheric pressure is about 1 bar. Going underwater the pressure increases roughly by 1 bar per 10 meters. So a 3 atm rating would imply 30 meters water-resistant.

I wouldn’t wear a device in a sauna which is stating in the manual that it’s splash-proof and you can wash your hands with it. The manual needs to state it’s fine for swimming for me to feel comfortable taking it into a sauna.

Operating temperature rating

Devices are usually rated with an operating temperature range in the manual of the device. For example the Garmin Vivoactive 3 manual states the operating temperature: from -20º to 50ºC (from -4º to 122ºF). The Polar Ignite states the operating temperature as almost the same: from -10º to 50ºC.

Even though a sauna is hotter than the highest stated operating temperature I wouldn’t be too worried about that. I have worn my smartwatches out during the winter in temperatures way below -20 ºC without any problems. Your wrist keeps the device warmer than the outside air. Similarly, your wrist will keep the device cooler in the hot Sauna.

I heated my home sauna and took my Polar Ignite into the sauna along with a temperature gun. After throwing some water on the stones I measured my skin temperature witch was around 38 ºC and the surface of the Polar Ignite was around 40 ºC so way below the max operating temperature of 50 ºC. After 10 minutes in the sauna, the results didn’t really change.

Which smartwatches can you wear in a sauna

I haven’t seen any smartwatches stating in their manuals that you can wear the smartwatch in the sauna so instead look at the waterproof rating and the operating temperature rating. The more important factor here being the waterproof rating since the operating temperature ratings don’t differ that much.

Look for devices that state in the manual that you can wear them while swimming. Personally I always try to select only smartwatches which are fine for swimming and I always wear them in the shower and in the sauna. I wear my smartwatch around the day and go in the sauna after the gym around 4 times a week and haven’t had a single device failure.

I can’t give you any promises on will some manufacturers say you are voiding your guarantee. On the other hand, I have never had to ask a manufacturer to replace my device due to water or heat damage.

Garmin smartwatches in the sauna

I would wear any Garmin smartwatch or fitness tracker in the sauna which is rated to be swim proof. Some examples of Garmin smartwatches I have worn in the Sauna without any issues include Garmin Vivoactive 3 Music, Vivoactive HR, and Garmin Fenix 5.

I checked the manual for the Garmin Vivoactive 3 and Vivoactive 4 and there isn’t anything about wearing it in the sauna. On the Garmin forum, a Garmin employee has responded to the question with a brief answer. “We would recommend using caution when using your device in an environment such as a sauna.” They also referenced the specs which state it’s 5 ATM waterproof and the operating temperate is up to 50ºC.

Since Garmin doesn’t state anything about how the warranty will be affected by using one of their smartwatches in the sauna I contacted Garmin support to get an answer. I asked specifically about the Garmin Vivoactive 3 and the response was that the product is not meant to be used in the sauna and if it is damaged during sauna use their guarantee will not cover it. I challenged them on this response since they don’t state that on their web page and the waterproof and temperature ratings would allow for different assumptions. Looking forward to updating this article once I hear back from them.


Apple smartwatches in the sauna

Apple Watch Series 2 and newer may be used for swimming in shallow water and you can take it into the shower. I wouldn’t wear an Apple watch in the sauna. I haven’t tried it but based on the Apple support page it doesn’t sound like a good idea. The Apple Watch Series 5 states it’s water-resistant up to 50 meters but not suitable for example for scuba diving.

The official Apple support page states: “The following may affect the water resistance of your Apple Watch and should be avoided: Wearing Apple Watch in the sauna or steam room.”

The Apple watch support pages also state that the watch shouldn’t be stored in temperatures higher than 45°C and it could shorten its battery life.

Polar smartwatches in the sauna

Polar Ignite in sauna

I would wear any Polar smartwatch or fitness tracker in the sauna which is rated to be swim proof. Personally I have really enjoyed the Polar Ignite which is rated at 30M water resistant and I have thus far used it in the sauna more than 50 times and I haven’t had any issues. I never have seen any moisture, steam or condensation inside the watch. The only issue I have had is that the watch is mainly operated by the touch screen and that’s really hard to use when it’s wet but that applies pretty much to all touch screens when they are wet.

I did check the Polar Ignite user manual and web site for anything about using the device in the sauna but they don’t mention that at all. So I contacted Polar support and they said they don’t recommend using the device in the sauna due to the high temperatures. This is a milder response than from Garmin since Polar didn’t state that the warranty wouldn’t cover the damage. I still challenged Polar on their response since they don’t say anything about sauna use on their web page and the waterproof and temperature ratings would allow for different assumptions. The temperature on the wrist is a lot lower than the overall sauna temperature. Looking forward to updating this article once I hear back from them.

Fitbit smartwatches in the sauna

The newer Fitbit models like Versa 2, Ionic and Charge 3 are all water-resistant to 50 meters and according to Fitbit, you can use them in the pool and the shower.

I wouldn’t recommend using a Fitbit device in the sauna based on what Fitbit instructs in their safety instructions: “Do not use your Fitbit product in a sauna or steam room.”

Quite some time ago I had a Fitbit Charge HR which wasn’t water-resistant and they even recommended drying it after sweating. It was quite bothersome to remember to take it off when going in the shower. Fitbit has naturally improved since then and the devices are now water-resistant but I still have the feeling that they aren’t quite as far with waterproofing as the likes of Garmin and Polar.

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