Kane heat mats are the ideal way to provide heat to tortoises in outdoor heated hideboxes. They also work well indoors in larger cages. These ultra-tough heat mats are virtually impossible for tortoises to damage. We use them on our biggest sulcatas with no damage. They are rigid and have a thick polyethylene cover on them that can hold up to any messes and wastes your tortoises throw at them. They can be swept or vacuumed off as needed. Insulated on the bottom, they are designed to radiate heat to the top side only, and we have never had one of these mats stop working. A very gentle heat, they aren't hot enough to burn tortoises, and we suggest not covering them with any substrates. We have multiple sizes available with varying wattages.
We have found it best to screw these mats down to the floor one way or another in order to keep them from sliding around or any tortoises or tortoise messes getting underneath them. They can also be mounted to the rear wall or the ceiling within a hidebox.