It may be something else overheating, Carbs, Coils, vapor lock....the fuel tank can get hot....Honda air cooled engines really rarely overheat if not abused. My CB350 once got hot, but I was riding it off road, deep side, slowly, with high RPMS to keep moving. It got very hot (Smell) but continued to run ....
I suspect you have another issue. My CB360 would behave like yours (not overheating) and it turned out to be a carburetor rubber manifold that did not leak air cold, but would leak and lean out the mixture after about 15-20 minutes or riding. The bike would run worse and worse, then wouldn't start at all...cold, one kick start.
I'b be checking those things....