What the??

OK, so I have been using a set-up where I had the UTH & a red lamp on the warm side for heating purposes. I had two humidity mats in the tank, one on the cool side & one in the middle, a water bowl, a hide in the middle & a hide on the warm side. With this set-up, i was able to keep the warm side between 88 & 94. After i hung out with Hissy today, I made a few changes. The changes made were mostly for the sake of humidity. I put the heating arrangements back the same as they were before. All of a sudden, about 45 minutes after i put her back the tank, the warm side was almost 100 degrees!!! Mind you the temps out here have done nothing but drop a little bit over the last few days so this did not happen because it got warm out or anything!!! Immediately i took the lite down & I turned my rheo-stat down a bit. All day long now since then, my temps have stayed at the 93-95 mark on the warm side with ONLY the UTH!! How in the hell could this have happened?? Why, all of a sudden, is the UTH plenty of heat!!?? Does this make any sense to anyone!!??

You didn't describe the changes you made. Good chance the thing that changed was the location of your thermometer probe. Just a small change in that can give you a very different reading. It's possible you may have had hotter temps than you realized all along, but didn't notice because the probe wasn't in the hottest spot. Or the amount of substrate insulating the UTH changed? You said you made changes for the sake of humidity...was one of those changes to reduce the amount of ventilation? That will not only hold in humidity, but heat as well. It could be any number of things.

What is the best way to set up the thermometer probe, to make sure it will take and accurate reading and not get in the way of your snake?

I buried the cord in the substrate and let the probes rest just on top of the substrate. My snake, at least, doesn't seem to notice them at all. And it might be good to shift them around from time to time. You could get a very different reading just an inch or two away from where it usually lies.

I think that the biggest difference is the instead of leaning the thermo/hygro up against the back wall, i now have it laying directly on the substrate. I think that i must have been torturing this poor girl with temps that were too high all because I thought that i did not have it hot enough! I don't use the probes because Hissy gets herself tangled into the wires so I put the probes under the substrate & just use the reading I get from the unit itself. It is stabalized now because I turned the rheostat down & the temp has been in the 92-95 range all day long. It has allowed me to use the heat lamp, at a greater distance, to increase the temp on the cool side just a touch. It has stayed around 78 lately, just a couple degrees higher, but important i think. Plus, with the changes that i made, the humidity has been an average of 50 in the tank. We have 40% in the hottest spot & 60% in the coolest. She seems really happy too. Whenever she wants a little more moisture, she crawls around on the humidity mats. She is too cute!

Sounds like you're getting things adjusted well. :)