Check cpu temp - how?

Don't panic at a big number under load either. Plenty of current CPUs are designed to boost until they reach the high 80s or 90s and sit there. What's worth looking into is it hitting that ceiling and the clocks dropping, or high temps at idle. That usually means dust in the cooler or a fan not spinning, and on an older machine dried-out thermal paste.

Task manager won't give it to you, which is where most of an evening goes - it shows a gpu temperature and people assume the cpu one is buried in there somewhere. it isn't. with nothing installed, restart into the bios and it's usually on the first screen. otherwise a small monitoring tool like core temp or hwinfo, or ryzen master if you're on amd. idle in the thirties or forties is ordinary, and it's the sustained figure under load that tells you anything, not a one second spike while something launches.