Why don't "dome" light fixtures overheat?
"Domes" are the type of fixture where there is no airspace between the ceiling and the dome shaped glass cover. I purchased one recently. It has a big sheet of insulation over the top of it, so not much heat is going to escape through the electrical box were the fixture is attached.
I plan to use LED bulbs in it, but I'm curious why heat isn't a problem in such fixtures when incandescent bulbs are used.