Is there anything I can temporarily put under substrate to prevent burning?

[rickm]

You are gonna need to set it to where it allows you to achieve proper temps and depending on how stable your room temp is you might need to adjust it daily.

Really?

A thermostat is the single most important piece of equipment, cutting corners is not only dangerous for your animal but can also become a fire hazard.

not sure what you are talking about, but done properly this is just as safe and affective as ANY other type of heat regulating device...and is no different(other than maybe better) than the zoo med or other rheostat type units you can buy at a pet store. I have been keeping and breeding for over 26 years, and have used the rheostats I make myself for at least fifteen years with no problems at all...and they are more reliable than most other dimmer type regulating devices I have ever used.....I like to use them on my racks that are taller and one thermostat has a hard time keeping consistant from top to bottom. I am talking about rheostat controls here, NOT thermostats....and all a rheostat is, is a fancy word for a dimmer or ramp(all it does is controls the amount of electric current goes to the heating element).