Regulating Temperature On "Cool" Side of Tank

I know that a UTH should be used to heat the "warm" side of the tank, but what I want to know is: how do you keep the temperature on the "cool" side of the tank from dropping too low? And if it goes down below 80 degrees Fahrenheit how do you warm it up?

The cool side will be determined by the ambient room temp usually.

If the room that the tank is below 75 a second heat source will be needed.

Check out this thread on cage heating:

http://ball-pythons.net/forums/showt...04#post1845904