My goodness no. That wasn't informed at all. Once they are feathered out at 5 or 6 weeks, they'll be just fine with nights in the 50's. They are wearing down covers and they'll huddle with their mates for extra warmth and a feeling of security. Naturally hatched chicks, by a brooding hen, would never still be under the hen's wings at that age, as she'd have booted them out away from her long ago.I live in Maine and it can be in the 50's at night. I was told that they needed the heat at night until they were 10-12 weeks old!