Heat really doesn't degrade CPUs until it's in the outrageous numbers like 100c+, which you won't get unless you like run it without a heatsink or some shit lol
Voltage increases are what really degrades your CPU and shortens it's lifetime, you could run at 1.75v 24/7 and have a processor die in a year vs having a processor running at 90c 24/7 and it last 5 years. Obviously guesses, but the point stands.
So as long as you're not getting outrageous temps (look up the temp your cpu is rated to run up to, should give you a guideline of what to look out for) you have nothing to worry about. Using the processor at 100% won't degrade it either. If it's solely a botting PC just run as many bots as you possibly can. If you wanna browse the internet I'd do like Noodles said and try to stay around 80% usage on just bots.
GL, if you need to check temps a good program is AIDA64. Not sure if it's free, I just dled the trial version and found a serial online, but it's a great program for monitoring temps and seeing other various info about your pc