Can code damage hardware?

Can random code damage your hardware when run in Real Mode? If yes, give some examples how. What happens when the ACPI tables are overwritten? Is it possible to disable the CPU fan through code, and have the CPU overheat and break, or does the BIOS have moron-proof failsafes incase someone would do that?

Yes, if you happen to poke the VRM controller/clock generators in the wrong way.

(Ask yourself how you can change voltages and such in the BIOS. I still prefer DIP switches or jumpers for this sort of stuff that shouldn't be under the control of software.)