Are you actually measuring the temperature of the hot spot on the floor? If not you definitely should be. Those UTHs can get WAY too hot. Is your BP hanging out on the hot side at all? An unregulated hot spot could be a part of your problem. You should really have a thermostat to control that (you can get a cheaper on/off kind for ~$30), and failing that, at least a lamp dimmer and thermometer with probe (but you will be in there several times a day adjusting it if the room temps aren't extremely stable). If you do not have a thermometer on the hot spot, or any kind of regulation, unplug it until you do, your BP will be better off with too little heat, than too much.
ETA: I personally do not agree with what NYHC4LIFE8899 said. A thermostat isn't necessarily needed, but I have run my Zoomed UTH full and it gets up over 125F. That is not an ideal, nor is it a safe temperature for a BP. At the very least you should have a dimmer and be measuring the floor temps with a probe thermometer or temp gun.