I've experienced something similar. Our power went out for awhile during two of my hatches. The first time I wasn't home and came back to find that the upstairs AC didn't come back on and my incubator was up to some ridiculously high temp, I don't even remember what it was, just how angry I felt. Needless to say, none of the chickens hatched although they were fully formed in the egg. My quail had hatched the day before and managed to survive being baked in their brooder.
The second time I was home and watched in frustration as the temp dropped lower and lower, down to about 95 before the power came back on. I had a pretty decent hatch; there were a few chicks that had crooked toes but they straightened out within a couple days and are right as rain now. They are pretty hardy little things and yours will hopefully hatch none the worse for wear.