I have accepted all the 'risky' things lm-sensors
wanted to do with my system since this answer told me so. My computer is now getting a lot hotter than before, even outside of Ubuntu, and I think it is due to that.
How to undo whatever changes lm-sensors
has made to my system?
lm-sensor
can change something at the NVRAM (Bios) level. In that case only a full BIOS reset can return the system to its previous state. How to do that depend on the specific computer/bios. – Rmano Jun 30 '14 at 18:28