{Gameplay} Game keeps crashing every ARAM game.

Every 2nd or 3rd game the game keeps crashing every time I've played ARAM. I get a grey line on the most of my screen and the game just outright dies, killing every other process that's been going at the same time. Last time I checked, it said the problem was in my CPU overheating (and after checking task manager, that does seem to be the case), and the way to fix this was to change the graphics settings, but that's didn't help at all. Occasionally, I would get the same crash on Rift as well, but ARAM seems to be the most common. Any suggestions? It's only on League, no other game does this, even triple A games. If I get a chance, I'll get a screenshot of this nonsense.