Ambient Vs. Surface temps heating question

[presspirate]

I'm working on a couple of enclosures, and I am debating how to best heat them. The cages are wood, so I am considering flexwatt under a plastic shelf liner. But my question is will that only raise the surface temp of the floor or wall, or will it boost the ambient temp as well?

I have 2 4'x2'x1' plastic cages that I heat with a uth and ceramic heater tied into a rheostat. The uth heats the wall, and the ceramic boosts the ambient temp. So the air temp on the warm side is around 88 but the surface temp on the wall is slightly higher.

I'm hesitant to use any kind of light inside the cages I am building, cause I don't want my snakes getting burned.
Thanks in advance!

Edit.( Maybe this should be in the housing/caging thread.)