cgsecurity.org

I didn't know why my pc was having this overheating problem, because checking with gnome-system-monitor there wasn't any process that was using CPU resources.

But then, I checked with "top" via terminal, and there was a testdisk process with 100% cpu usage that was causing an heavy overheating and fun loud. After I killed it, problem was fixed.

Version of testdisk: 7.1

Try out using version 7.2 WIP to see if your load indicator rises to 100% again.
Modern CPUs slow down cores to prevent overheating so it would be interesting to know what you consider as overheating.