I'm hoping someone here can help, I hatched out 6 eggs (2 Friday, 2 Sat and 2 hatched on Sun) in a small outdoor coop seperated from my flock. Our temps dropped drastically overnight Saturday and we got snow on Sunday morning and before I got out to check on the chicks (last I had checked on Saturday they're was only 4 chicks hatched) on Sunday morning 4 of the chicks had died. I assume from the cold? The temps were to drop again so I moved momma hen and her two chicks inside my garage into a brooder. Now I want to know at what outside temp can I let them go back out to their coop and they'll be safe? They spend less time under momma as it's warmer in my garage, will she allow them to go back under her in colder temps? They are less than a week old. and being Bantams very tiny! Some have suggested a heat lamp outside but I am afraid that will be too hot on the momma who is used to cold?
Please help! I have more chicks on the way and I need to know what to do? Temps to stay in the 40's for while I hear with a few 50's thrown in. Below is the coop they were in. They are Bantam Cochins

In the brooder inside

Please help! I have more chicks on the way and I need to know what to do? Temps to stay in the 40's for while I hear with a few 50's thrown in. Below is the coop they were in. They are Bantam Cochins
In the brooder inside