Thanks for letting us know here about your experience with your Samsung Galaxy Note 8 having issues with screen froze then turned suddenly turned off. It seems that your device has restarted to protect it from overheating. Should the issues persist, we highly recommend bringing it to the nearest Samsung authorized service center in your area.
Rest assured that your device will undergo an assessment to pinpoint the root cause of the issue. They may guide you and offer solutions to restore it.
or book an appointment with the Samsung Members app as follows:
Support > Book an appointment to set one.
Should you need further assistance and guidance, you may contact us via our online Samsung Customer Care support channels below.