Maybe I should have been more detailed in the original post as I was trying to remove these concerns before they popped up.

I was using the repti bark to start off, but it was easily moved around and didn't stay put. The repti bark was also having issues holding the humidity very well. I have always just had much better luck with cypress.

The substrate isn't very deep here, but I must reiterate that the probe is directly on the flexwatt just as the probe for the thermostat is. There is something in between the flexwatt and the substrate. It was usually a couple degrees cooler than the reading on the 'actual' bottom of the enclosure. Also the other Accurite probe was reading 2 degrees less than the one pictured. I used a temp gun to verify and everything is within safe levels.

I promise you that I have considered temps very carefully and tested before putting the animals in. Thank you for the concern though, it is much appreciated =)