About 2 weeks into incubating we had a power outage a couple of years ago on the coldest night of the year. The incubator was at 78 degrees when I discovered the power was out. I had covered the incubator because it was so cold out that night and the heater in the room the incubator was in did heat the room somewhat. This was at night so the power was out for quite awhile before I noticed it. I just happened to wake up and noticed my night light in my bathroom wasn't on. I hooked the incubator up to a battery with an inverter and brought the temp back up. It spiked up to 115. I was sure I had lost all of the eggs. I candled the eggs the next morning and saw movement in some. Surprisingly, I still had a decent hatch.