https://wccftech.com/apple-releases-watchos-7-0-3-for-apple-watch-series-3-that-fixes-major-issues/

Today, Apple has seen fit to releases watchOS 7.0.3 for Apple Watch Series 3. The update comes a week after the release of watchOS 7.0.2 that fixes a major issue faced by users of Apple Watch Series 3. If you decided to not upgrade to the Apple Watch Series 6 and want to continue with Series 3, you should definitely install the new update. watchOS 7.0.3 brings fix for unexpected restart issues faced by the Apple Watch Series 3. Let's dive in to see some more details on the subject.

If you own an Apple Watch Series 3, watchOS 7.0.3 can be downloaded via the dedicated Apple Watch app on your iPhone. All you have to do is head over to General > Software Update. Before you install the update, make sure that your Apple Watch has over 50 percent of battery life and plugged in a charger. Also, make sure that the Apple Watch is in the range of your iPhone.