Hop over to BOINC. These folk run 100% 24/7.
Variable speed CPU fans run wide open under these loads (I have worn out 2 on a CELERON that BOINC adds 100 Watts to the Computers power consumption over idle).
The down side is the room gets warm

without A/C
Keep your fan blades clean, Grills and fins (mostly) lint free.
Most modern Motherboards have CPU overheat protections (clock throttle, then shutdown).
BTW you are wasting CPU cycles if you are not using 100% of them