Have 2005 4500 Kodiak Diesel, looking at fuse panel on passenger side under dash. #8 fuse is really hot to the touch. Is this a fuse or is this a breaker? Took to dealer to see if something wrong with circuits. They could find nothing wrong. Is it normal to have these breaker/fuses hot to the touch. If there was a short problem, they would trip. Won't they?

They are breakers and will get hot. They will trip if too much current is there. As long as the correct amperage breakers are in place they should be ok.