Go to Walmart and buy two accurate thermometer/hygrometer's. They are digital 2-in-1 devices for like $10 each. Put one on the warm side, one on the cool side. That will give you better humidity and temperature readings. Your UTH NEEDS to be on a thermostat. Period. If you don't have one, you can get one on Amazon for about $40, or if you have the money, invest in a Herpstat. It's $100, but well worth it. To keep ambient temperature up in a cage that size, you either need to heat the room, invest in a 100w CHE (ceramic heat emitter), or an RHP (radiant heat panel). You'd have to modify your lid a little for the RHP, but it would help.