I know a lot of you are thinking I'm nuts to worry about these gals already and it's not even winter or the middle of summer, but look at the max/min temps the pullets have to deal with when the seasons change. Those temps at the bottom both happened since about 4 o'clock this morning. We have some big temp swings out here.
We live in an area where overnight lows of 29F can rebound easily to 81F and then plunge again to 29F overnight lows. 50-60 degree swings is quite common. The birds adjust, as do the robins, the wild turkeys, the eagles, and all the other wild birds. They are tough and not sissies. If they were not tough, they'd never have survived and thrived as well as they have for the last 4000 years.