That's the tricky bit! A lot of people tend to keep reptiles too, so a reptile room is ideal as they're generally warm. Otherwise I put an oil radiator next to the cage, a pouch on the same side as the radiator and one on the other side and one in the middle and they have a warm side, a cool side and an inbetween
. I also tend to increase their food, keeping warm uses energy and if they run out of energy that is when the real problems begin!
