I'm so very sorry to read of the loss of your snakes. Personally I prefer using flexwatt controlled by a good tstat (or a rheostat in a pinch). I also get Rich from Reptile Basics to wire all my flexwatt, which he does for free as long as you buy the wiring kit. I don't trust my own skills with that so I figure have him do it.

Why type of UTH did this damage? What type of tstat? When you say too big, how big was too big? Sorry for all the questions but I always figure in each tragedy like this, if we can learn something from it, then it's something to hold on to.