I have 2- 8 week old fully feathered White Rocks that need to go to the big coop. It is in the 40- 60 degree range. I can isolate them in the coop till the big girls accept them. I just worry about the cold. A heat lamp could be put in with them but the light would be on all the time and I don't know how the big ones will take it. Any suggestions? The White Rocks are in a heated barn with 8 misc 4 week olds in a 4x8 brooder. The temps in the brooder under the heat light are in the 80's but at the cool end it is in the low 70's. Any advise would be appreciated. John