I unplugged the UTH and will keep it off until the thermostat arrives. I have the evening (red) heat bulb on. I've also placed a space heater that I've used for my bird next to the tank on low heat - it should help to keep the hot side warmer, but not too warm.
I probably won't get any sleep tonight because I'm so worried about Oliver. He was very active, climbing and exploring all over the place when he arrived. Now, he won't come out of his hide. I'll be distraught if the temp problems injure him.
BTW: none of the websites and books that I've read mention a thermostat. I would have had one if I knew that I needed it.....