PC restarts when playing games

[Kamen]

So my PC will shut out with no warning and restart after 2 seconds when i play games (Dota 2, Divinity 2, Fortnite). When the graphics are high it happens really quick. When i set it to lowest it happens at the more graphic-demanding moments and after that it may occur more often. 

At ubuntu i've tried dota and it rarely occurs at the highest settings.
I also noted that when i plug a usb flash it gets hot after a minute.

 

Intel Core i5 4690

8,00GB Single-Channel DDR3

MSI B85M-G43

GTX 970

TEAM L7 EVO SSD  (Windows 7 Professional)

TOSHIBA DT01ACA100 (Ubuntu)

 

Thanks in advance

[Leg_Licker]

It could be getting too hot.

[RoyalGamer1]

yeah check the temps it sounds like it could be over heating.

[Kamen]

I don't see anything going beyond 50 C, graphics card at most 75.