Denny, I'm working on the UL approval...
I think the baffle on the top is a good idea, so I might try something later. I've only used it for a while, but with the low 25W bulb I've got in there doesn't get "hot". I've still been able to touch the metal can. It's really just a warmer. The coldest my basement gets is 60 degF, so I'm only needing to raise it 10 degF. If I needed more, I'd honestly spring for one of the heating pads.
Also, comments on a larger can. My constraints were that I needed a small can due to using it in a dorm fridge.
In the full post, I mentioned finding on a UK site some "greenhouse heaters" that looked perfect, but I couldn't find them here in the US.http://www.berrybrew.co.uk/fermentation-fridge-build-brew-fridge/
On the reptile heaters, what is everyone using?