The iPhone 16 series has been suffering from a curious bug—random restarts. People using the iPhone 16, 16 Plus, 16 Pro, and 16 Pro Max have reported that their phones have been restarting on their own for seemingly no reason. Plenty of people have posted confirmation of this problem on Reddit and Apple's own support forums, and now Apple has acknowledged the problem and confirmed that a fix is coming with iOS 18.1.
At the moment, there's no clarity on exactly what is causing these random restarts, but those facing the issue have reported some details that could help. Most importantly, it doesn't seem to be related to third-party apps, since users with fresh out-of-the-box iPhones are still seeing the random restarts. Instead, it's most likely that an iOS 18 bug related to system apps is causing the problem.
If you're facing a problem with a randomly restarting iPhone, the easiest solution will be to wait a few days until iOS 18.1 is released. Apple has promised a fix for the problem in the update's release notes, saying "Fixes an issue where iPhone 16 or iPhone 16 Pro models may unexpectedly restart." Currently, the beta version of iOS 18.1 is in the release candidate stage, which means that the final build is just about ready for the general public—it'll be released sometime next week.
You could also download the public beta and update to iOS 18.1 immediately, but with the final version right around the corner, I recommend waiting a few more days to get the release through the stable updates channel instead. If you forget to turn off beta channel updates, your iPhone could face issues such as increased battery drain or crashing apps. Apple may also refuse to service devices that are running an iOS beta.
A fix for the random restart bug is one of many changes coming with iOS 18.1. The new version also includes some Apple Intelligence features, call recording, and an option to reset the Control Center to its default layout.