The thermostat should keep it from getting hot enough to matter. At most the UTH will hit 105 F, but in most cases the Thermostat should be set in the mid to upper 90's nowhere near hot enough to cause any problems (we humans are 98.6 F after all) Even at 130F most surfaces will be fine. I wouldn't set it on carpet, but most other surfaces should be fine.
Here is how I have mine set up:
don't mind that it's centered on the cage, The cages I use actually have a divider running down the middle so I put the UTH in the middle so it can heat both sides at the same time. You can see the outline of where the UTH would go if it wasn't using the divider. You can also see a slot cut into the bottom of the cage for the thermostat probe.