Being in the BIOS dosent put a load on your processor, since the BIOS is a physical chip right on your motherboard, the processor is never needed to access it or configure it. I was going to suggest that it is because you are overclocked, but then you said it was the same problem before you overclocked, so that made it a little bit more difficult.
Try going into the BIOS severla times, at different points, and recording each time what the starting temperature was. If, say, when you go into the BIOS and it starts at 100 and it goes to 115, and then you restart and use your computer for a while and then go back into the BIOS, is the temperature back at 100 and starts to rise, or does it start to rise from 115?
No question is dumb, dont sweat it. Everytime you ask a question, you learn something new. Does anyone see a problem with learning something or the will to ridicule someone for wanting to learn? I certainly dont.