After play game about 2 hrs. AA:PG Draining CPU and fps drop

After play game about 2 hrs. AAG Draining CPU and fps drop

how I can fix this?
It's never happened before
Spec:
C: I5-4570
R: 12G
V: GTX 650 (Boost 2)

 

Could be temperature related. Use something like MSI Afterburner to log temps for CPU and GPU. Maybe strip and clean PC anyway.

 

Thanks, I'll try to use Afterburner. But I installed OS 2 days ago.

 

Bf1, csgo, lastman, rb6 and other games had no problems