I go at 87. It was recently chilly, and since I have the probe on the FW in the Inc. and not inside the egg tubs, that is why it has been 86.5 the past few days. But it is maintaining at 87 now. I am just paranoid about eggs being cooked to death, as I had that happen with a crappy hovabator recently. But this seems to be working fine. Like Raul said, if our house heats up a few degrees, they will not go into the danger zone.