Right, they might notice it, but why would they care? They don't know that they should care, it is just a computer being a computer and it probably spins up the fans for other tasks too. They would be right to not care unless told otherwise, sys ops isn't their job.

I think it would be smart to educate people as part of a regular security briefing for non technical staff though. But if it's something that high of concern to your company maybe an automated CPU usage monitor could alert the team to anomalies.