Actually I learned from my snake that I was allergic to pine and cedar. I broke all out. I should have known as my dad is allergic but oh well. Now, for the UTH is her cage is 4 ft long by 18 inches wide, what size UTH should I get? Like do I need it to cover the whole length? Or just maybe half? Also can this thermostat hook into two different UTH?

Sorry. I have never owned a thermostat. Trying to make sure I pick out the right one.