When I first started out I used a on/off switch thermostat for Sammy. I bought a heat temp gun and checked the hot spot temp. 77 DEGREES!! That thermostat didn't do anything! I'm glad it stayed lower at a lower temp than at higher temp, burns are nasty!! Just found a barely used Herpstat 1 for just $75. Moral of the story, please get GOOD PROPORTIONAL thermostats.