PC shuts down after about 20 minutes of playing.

So after the maintenance/patch last night my PC keeps shutting down while playing the game for about 20 or 30 minutes. I don't mean like freezing or crashing, I'll be playing and all of a sudden my entire computer just powers off. I know it's not my system because I've updated my drivers and I can play other games perfectly fine.
Anyone else having this problem or have any suggestions for a fix?

Cause: Your PC is overheating and shutting down to protect itself from heat damage.

Fix: Open your PC and clean the dust bunnies out.

I suppose I can give it a try, but if that was the cause then wouldn't it shutdown when I play other games like Skyrim with graphic mods and Battlefield 4 and The Witcher 2 on max settings?