The Apple Watch Series 3 is Apple's latest offering in its range of wearables. Equipped with cellular bands this time around, Series 3 seems to be facing some issues for users in hospital premises, especially around the ICU (Intensive Care Unit). Users have complained of random reboots while around the ICU in hospitals.
As we mentioned, some Apple Watch Series 3 users are experiencing an unusual issue wherein their device keeps restarting randomly, while at a hospital, at least once every 60 minutes. A user on an Apple Support forum thread, as reported by 9to5Mac, states that the bug is present on watchOS 4.0 as well as watchOS 4.1 of the Apple Watch Series 3. The comment also claims that the issue is apparent on different iPhone variants; in this case, the iPhone SE and iPhone X.
Some users mention that the issue is present on both non-cellular and cellular variants of the Apple Watch Series 3. Other models like the Series 1 and original Apple Watch do not seem to be experiencing the restarting issue. This could be a result of an interference of the wearable's internals with medical equipment. The Apple Watch User Guide mentions that the "Apple Watch contains magnets that may interfere with medical devices." However, this does not explain why the issue is exclusive to Series 3 units.
A lot of comments claim that steps like repairing the Apple Watch, updating it, or even replacing it do not seem to resolve the issue that is oddly faced only near the ICU in an hospital. Putting it in airplane/ flight mode seems to be working for some users, although it disables most features of the Apple Watch Series 3.
There is no official acknowledgement from Apple regarding this issue. Once acknowledged, however, a software update might be able to resolve it.