A thermometer inside the cave won't do much good. The cave works by the chicks having their backs up against the warm pad, not by creating ambient heat. Here are the general guidelines (I would start on high):I've got the wire scoped out to make the cave with and a thermometer to put under it to test out the temps at different settings.
First IT IS REALLY ANNOYING THAT THE MENU ITEMS DO NOT WORK!
* If the chicks won't come out, the pad temp is too low
* If the chicks won't go in, the pad temp is too high
* If the chicks come and go, the pad temp is JUST RIGHT.