PC Freezing Due to Overheating all of a sudden Please Help!

helpplease12321

Prominent
Nov 11, 2017
6
0
510
So my PC has randomly been overheating a lot recently. I play League and my FPS used to be around 150+ in teamfights and 200-300 in the base. Recently my FPS has dropped to 80-100s in teamfights. My PC has also been freezing due to overheating and my program called Core Temp says my PC is running at 70-80C while I play league now. My PC used to run 60C at max and I have no idea why my computer is overheating so much. I know my PC is not that clean it is pretty dusty and I need to clean it but that shouldnt increase it by 20 Degrees! I built this PC a year ago and it never had any problems till now. I'm not that good with PC stuff so I'm not sure what to do! Any help would be great, this is my build
https://ca.pcpartpicker.com/list/rNyzmG

My Computer also runs around 31-66C just watching YouTube videos... which is really high.