I build mine out of 1/4" plywood screwed to a frame. I could only get 90 degrees in the winter out in the unheated garage until I insulated it with cheap foam board, it will get really hot now, I have never maxed it out so I don't know how hot. I use three lights on a dimmer switch and have vents in the top and bottom for natural convection for air flow. I built a shelf about the center of the box to disperse the heat and keep the wood away from the lights.