My coop is insulated and I have a heater on in the winter when it gets cold. But I live in western Wa it doesn't get very cold here for very long. So far I am having better luck keeping my serama chicks alive then my silkies.
None of my mystery eggs hatch though I had 5 try. We had really great weather and iy made my incubator go up to 102 during the day and 99 ay night. Lost quite a few of my seramas too. One of them made it to lock down.