Dude, if the heat is too much,

Try a sealed hood for your light. Or a Cool Tube. Mellow Man has a good FAQ. And I built a cool tube for under... um, ... um... . under... something like under $50. Works wonderfully.

As to closing your cabinet; that's a bullet you're going to have to bit sooner or later... I mean, when they start to flower: what about the smell?

Peace man,

-turtle420