I'm incubating eight goose eggs (in a Hova-Bator 1602N), and I read that the temperature is supposed to be 99.5 degrees. However, the incubator temperature seems to fluctuate an awful lot, from 96 to 102. I have two thermometers, one of which I know is pretty accurate. This is probably partially because the room the incubator is in isn't insulated or anything. In our warm climate, nobody needs heating (although lately it has been dipping into the fifties at night). The incubator is in one of the most stable rooms we have, so there's not much we can do to improve it. So is a temperature difference of up to 6 degrees going to be deadly?