I made this one for a female hermanns tortoise to see if she will stay active longer this fall while outside. To heat it I am using self regulating heat cable wrapped around the outside, using tape to hold it in place. Them wrapping it in aluminum foil, this helps to disperse the heat more evenly. Next is the insulation, using a flexible rubber type normally used for cold applications. a little moisture doesn't lower it's insulation valueThen the vapor barrier to help keep things dry.This is an embossed peal and stick aluminum jacket. End caps first and then the body Spray painted it black According to my kil-a-watt it will use between 6 to12 watts to keep the inside temperature 15 to 17 degrees F above the ambient surrounding temp.using 75 degrees as a test temp.