Same issue here. I bought the watch Jan/2019, and since last week, suddenly happened. Watch started overheating and won't even stay turned on more than 10mins. After turn on the watch, it overheats immediately, and giving me warning “watch needs to be cool down” and turn off. Tried reset watch, uninstall wearable app and re-install. nothing changed. I haven't been able to use the watch for a week.
I truly regret the purchase.