I have a couple zoo meds they are fine. In a max temp test (no snake bare enclosure plug it in to the wall unregulated and watch and wait to see what happens) I stopped testing at 163ºF. The ultratherm (intellatemp/kane/others?? I only know these three) in the same test hit 98º and sat there for 18 hours. It is nice to know that if things go very wrong you have unhappy snakes rather than roasted snakes. When there is safer alternatives why not use them? It is silly not to. There are safer alternatives to the zoo med UTH.