My thermostat probe for the hot side has the wire running under the substrate under a rock, with the probe wedged between the rock and his hot hide (I use a CHE not an UTH) only time it is a problem is when he decides to lay on it - which luckily he does not do often or for long amounts of time. But, yeah - making sure everything stays where I put it is a pain. Thank goodness for IR guns
I have the thermometer probes either hot glued or drilled in place. I have an AP cage and custom drilled some small holes in the bottom so that each hide can have a digital probe too for measuring ambient temp. does not matter if he lays on those