PC restarting randomly while gaming

[The TridenT]

So I have a Nvidia Geforce GTX 660ti 2gb and I've been monitoring my temperatures while playing games such as battlefield 1 and PLAYERUNKNOWN's Battlegrounds becasue my computer has been shutting down randomly without my consent while i am playing (I'm on low settings, too). I know my cpu is doing fine, but my my gpu's max temps are getting up to 86 C. Could this bee overheating, thus causing my pc to shut down? My only other thought is that it could be my power supply causing these random restarts because its gone bad and not supplying my other components with enough power. What could be causing these random pc restarts? Thank you.

[genexis_x]

Bad PSU, dying GPU etc

86℃ is high but not overheating.

[Ertman]

No expert here, but agree with the other poster as that sounds like a PSU problem or power delivery problem.

[The TridenT]

Alright, thanks.