Laurisch wrote:
Nonsense. This happened to me in water of 26 degrees - my body temp is 36 so it definitely wasn’t too hot either. Why have swimming on the activity app if you can’t swim with it Apple?
Assuming a swimming-rated Apple Watch, 26℃ swimming should not cause a battery issue, though temperature still seems the most likely cause of the symptoms reported by the various folks in this thread.
I’ve swum in water only slightly warmer, and with no issues.
Contact Apple Support.
The battery health estimate mentioned earlier may well be incorrect and the battery more marginal, or your (unmentioned) battery health may be 80% or lower and might actually be marginal.