There will be a low of 65 degrees tonight, and I put them out in their new coop. There are 7 of them, so even if they are a bit cold, then can huddle, right?
I live where it's still getting down to 35 at night, I keep chicks in a home-made brooder, 2'x3' and have an 85 watt red bulb for heat. At 4 weeks I put them in a little coop with a run, same light is on inside until about 51/2 weeks and then I let nature take it's course, and I've never lost any. Maybe this helps???? Taker Easy!!