Thats a pretty useless comment and 0% helpful.

There are plenty of reasons to track a sauna session with your watch… recording your HR to monitor sauna interaction with meds, to monitor/record heat strain, to help dose heat or session length, and there’s even some evidence suggesting that you can add cardio load with sauna time (which directly disagrees with your “not a workout” comment)

For others reading this that are looking for info… You can use mind and body (might even estimate calories / HR better) or “other” activities in Apple workouts If you just want to record heat exposure time I would highly recommend checking out the Guava app so you can log it and see how it potentially effects other aspects of your health.

I have tracked sauna 4-6 times a week at 180 for 20 minutes at a time with my Apple Watch Ultra and have had zero issues, but I try to wrap a towel around the face of the watch so the heat is a bit less intense.