cpu – Extra wear of multicore processor when only a single core is used. Is there such a thing?

There are specific processes that seem to load only one of the processor cores, out of the eight cores my processor has.

I have some such processes that run only 10-20 seconds, but others run in this fashion for up to 1.5-3 minutes.

During this my cooling fan can speed up to really intense rates.

I was thinking, if there is so much heat to deal with, while it is being concentrated on only one core, then is it possible — considering the entire area of the processor — that some part is getting hot while the opposite end/corner isn’t so much?

When considering heat expansion in materials, shouldn’t it mean that the processor’s materials are under extra stress and may be driven to develop cracks from the uneven expansion?

Is this how it happens really?

Can there be a difference in this regard between processors used in laptops (smaller, I guess) and processors used on traditional format motherboards?