Don’t do it. I tried this once just to see what happened and my watch shut itself off from overheating after 15 minutes. Once it got back to normal temperature it was fine, but it really isn’t recommended.

I use it all the time in the sauna previously with my series 6 and now ultra 2. Always run the cooldown workout to track my heart rate and usually stay in for 10-15 minutes and have never run into a problem. Sauna temp usually at 200 degrees Fahrenheit

I’ve been wearing them in the sauna since series 2 and I’ve never had an issue, honestly I think the sweat cools it off a bit because I’ve never had an overheating issue, the phone will overheat if you don’t splash water on it every now and then

Took my Ultra in for my first time… After 9.5 mins, it shut down and displayed a temp logo with red in it.

The third time I used the sauna without the Ultra, I saw someone had an Apple Watch, so asked how his responded in this heat. He said it had never been an issue and had never shut down.

I then pondered aloud whether mine had shut down because it’s titanium rather than aluminium and might have conducted the heat more. He got up and left. I meant it as a genuine science conundrum, but he might have taken it as me being a tosser.

Yes, I have my garmin always so Apple Watch (ultra should so classic too) should too

On vacation in Mexico, I got to drop from a zipline into a cenote. Great experience for me. However, the Apple Series 6 watch did NOT survive the experience. Perhaps it was the nature of the impact into the water. Or perhaps it was the mineralized water. Who knows. Bottom line. Its water resistant. At best. Not water proof.

Apple’s docs state not to wear it in these circumstances. You can find them somewhere.

Anecdotally, I’ve never taken mine off at the spa. I go frequently, and do multiple bouts of 20 minutes in steam, sauna, hours in hot water, etc. I’ve not had an issue. The only place I ever take it off is at the beach, as the sand will destroy it.

Whilst it’s not recommended, I took my Apple Watch Series 4 into the swimming pool (that’s ok) and sauna, steam room and infrared room 3 times a week for years. With zero issues.

I now confidently take my shiny new Apple Watch Ultra 2 in there and had zero issues.

I disagree with everyone in this thread so far based on my own experience.

Had every watch from the OG to the latest Ultra 2, upgrading every year. Worn every single one in a hot dry sauna and my own personal home steam room. Not one issue ever. I always have AppleCare+ on them though. I also wear my AirPods in those environments. Never issues either.

I workout 4-6 days a week and use a sauna or steam room every time. Never had a single issue with any watch. YMMV but that’s my experience.

I take my phone and watch in the sauna often. Only issue I’ve seen was my phone presenting the high temp signage.

i wear mine without issues

I’ve never treated my Apple Watch differently than any other watch, worn it all sorts of conditions and it works fine.

I always use mine in the sauna with no issues.

I am unsure but using my Fitbit watch as my scenario I would say no.

I’ve been wearing my Series 5 in the steam room, sauna and hot tub 4-5 times per week for the last year. No issues.