You could do that, but I don't think it would project very much heat. You could put it on the floor and cover it with a piece of plexiglass, and silicone everything into place. If they needed extra heat, you could put a ceramic fixture in the ceiling on the cool side for a CHE or red bulb just for some extra ambient heat(guarded of course).

Melamine is just a pain to work with if you can't get those heat panels. I don't think you can router into it like other woods(might weaken it?).

I'd try an 11"x24" panel of flexwatt and see how that does.

What are you housing? Those new FWCs?