The hens survived a cold and windy night in the coop. It dropped down to about 60 degrees when we got home from swimming and rock climbing yesterday, so I added a ceramic heater to keep things warms. Four-week old chicks should be at about 75 degrees.
We have a wireless thermometer so we can keep tabs on the temp. It was above 80 when I checked at 3 am, so I went outside to make sure they were ok and they were sleeping on their roost, side by side. Very cute!