First of all your UTH should not touch the bottom of your enclosure. Air is the best insulator. Put the heater on the surface of your stand then place your enclosure on some 1/4' risers above the heater. You should have a space that is between the heater and the enclosure of about 1/4''.

One, your heater won't have to work as hard to keep up temps. saving you money on electric and replacement heaters.

Two, you won't have to worry about you snake getting thermal burns from a heat source that he/she is in direct contact with.

Hope I shed some light on your situation.