If you have been on the Internet, you might have read that iOS 11.1.2 has a serious issue. It keeps restarting for “no good reason”.
Of course, it was found out that this restarting is due to the notifications of 3rd party apps. I have read reports of users seeing their phones restarting non-stop.
Thankfully, Apple engineers had solved the problems and updated the software to iOS 11.2. If you have not updated yet, it is safe to update now.
This is from Apple Support page.
If your iPhone, iPad, or iPod touch unexpectedly restarts
If your device with iOS 11 unexpectedly restarts repeatedly on or after December 2, 2017, learn what to do.
Try to update your device to iOS 11.2. After you tap Download and Install, the download will continue even if your device restarts. Wait for the update to complete.
If you can’t update, turn off notifications for all the apps on your device, then update your device to iOS 11.2:
- Tap Settings > Notifications.
- Tap an app, then turn off Allow Notifications. Repeat this step for each app.
- Update your device to iOS 11.2.
- After updating, tap Settings > Notifications and turn Allow Notifications on again for each app.
If you’re unable to update or still have issues after the update, contact Apple Support.