Apple today released watchOS 7.0.3, the third update to its watchOS 7 Apple Watch operating system that was originally released in September. The update includes a fix for the random reboots that Apple Watch Series 3 owners have been experiencing.
From Apple’s release notes:
watchOS 7.0.3 contains improvements and bug fixes, including an issue where Apple Watch Series 3 may unexpectedly restart for some users.
The update is available only for Apple Watch Series 3 devices, and if you have another Apple Watch model, you will not see the update.
watchOS 7.0.3 can be installed on an Apple Watch Series 3 via the Watch app on the device’s attached iPhone. Go to “General” -> “Software Update” to install the new software. The Watch should have at least 50% battery life, be connected to a charger, and be in the range of the iPhone.