Review on REPTI ZOO Reptile Tank Heater: Waterproof Heat Mat for 1-40 Gallon Terrarium - Ideal Heating Pad for Snakes, Lizards, Bearded Dragons, Hermit Crabs, and Leopard Geckos by Roberta Berg

If you read the manual for this thing (three 8.5 x 11 half pages printed in reverse order) you'll think it's going to burn your feet and then just for fun the whole thing setting fire to neighborhood . I ran it for 4 hours, sitting on a cloth-covered office chair, and...no smoke, no burn marks, no ending-of-life disaster. I then put it in a plastic container (just experimenting) in which I store 4 rolls of 3D printer filament. I thought maybe the trapped heat could get too much with the lid on, but no, everything was fine, never over 85 degrees. The small temperature display, which turns red when fully heated, turns black when touched with a "cold" finger. According to my infrared thermometer, the temperature of this rug has never exceeded 118 degrees Fahrenheit. In fact, about the middle half of the center strip of the carpet heats up. Each of the outer quarters peaked at around 98. If you don't know, the minimum temperature for washing hands is 120. Perhaps lawyers haven't studied how PTC (positive temperature coefficient) heaters work. The heater itself is printed (like ink) and self-regulating, letting through less and less current as the temperature rises. While the PTC heater is inherently waterproof, the manual states that water should not even be near this heater. Repti Zoo's lawyers insist in huge letters that it can't be used on plastic cages (even on the outside). Since my plan was to put it in or under the box to keep my floss dry, I'm not sure this will leave me. A true adjustable thermostat would probably be better suited for this application, but the dialed temperature would be the same as that pad and without the extra components that create a source of error. Again, PTC is inherently safer than traditional coil and thermostat heating. So in the end I'm very happy with the safety and performance of this mat and I'm sure any buyer will be completely satisfied if used as directed.