the sides are 1/4in plywood but the bottom is melamine, we're gonna drill a hole and line a 6ft pvc pipe and place halogen lights in it since as my tegus get bigger they start climbing less i figured it would be ok...and for night time heat on the other side i'm gonna have 1 or 2 ceramic heat emitters hooked up to a dual timer outlet center..i was gonna use melamine but its to damn heavy for me to move it especially on carpet.