heating for wood enclosure?

[nita]

Hi all, I have almost completed my enclosure it is made with 5/8 inch chip board and I'm wondering about heating it. I have a heat light built into it but I also want to have an UTH of some sort and am wondering as to the best way to do this. The bottom and about 6 inchs up each side is tiled as well to allow for easy cleaning. So i guess:

1) can I adhere an UTH to the bottom of this, that would put it directly on the wood and I'm wondering about fire hazard.

2) would enough heat actually get through the wood and tile?

3) what would be some other ways of heating.