That still doesnt make sence to me. If the heat tape gets hotter then it would show in the tub as well. Therefore when the tub temp goes past 90 the heat will shut off. The heat will never get hot enough to burn an animal. I have never had a catastrophic failure with heat tape in that situation. I could understand that scenario if you were using a rheostat but not a thermostat. Even if the probe was in the front of the tub and you had a failure the stat would shut off once the front reached 90. If it got to 90 in the front at worst you would have 100 in the back and thats still not hot enough to burn an animal. Now if your thermostat fails thats a different story but i still have never heard of a snake burning in any of these scenarios.