@FeanBlickerAnother player recently fixed a crashing problem with an AMD cpu by updating the bios. Dunno if that's an option for you.
Also, try updating your graphics driver, I think the one you have is old.
As for heat, I've found that limiting frame rate works well. AMD has, in their software, an option to limit fps. Just try 60 or 65 as a test to
see if it helps anything. Using Vsync to limit your framerate may not help due to your 144 Hz monitor. Plus, vsync sucks.
Also, about the heat, it shouldn't cause a crash. The cpu will throttle down to a lower speed, which might cause some fps
drops, but generally not a crash. I'd look elsewhere for a cause.
Your windows event viewer may have information about the crash which could be helpful.
Does the computer shut down/reboot when it crashes, or just crash to desktop?