This question actually applies to the processors of yester-year meaning 2000-2001 era
Back then some CPU's, in Particular AMD, didn't have any thermal protection safety shutoff features like chips now.
How hot could processors actually get if left on?
Sry if these are too easy folks. I'm not as good as jak
Well back when they didn't have the safety shutoffs the CPU would keep trying to run until it the computer would either stop giving power to the motherboard, or it would keep going and sometimes cause a fire. These processors would get up to 325C+ whereas now-a-days you'll never find a processor getting that hot (newer CPU's and mobos obviously) simply because of the thermal safety shutoffs now implimented not only in the CPU's but the motherboards too.
Sorry the question sucked, but as I said I'm not as good as jak.