older chicks

[Nigellas]

Once they have all of their feathers, can they go outside without a light? Even when it still gets down to the 30/40s at night? They still seem so little, even though they are feathered out, am I just being paranoid, or is it best to keep them in longer?

 

[Fred's Hens]

You should be "conditioning" them each day/night to lower and lower temps. No shocks.
At five weeks old, begin the preparations. Keep lowering the wattage in the bulb, or raise it. On the night before going outside? No heat at all. You can also "step" them out to the garage, where it might be inbetween the house temp and coop temp.
By 6-6 1/2 weeks, they are fully feathered and completely capable of staying warm on their own, on nice dry bedding or on their roosts.
While nights are cool in April, they are no longer near zero. Come next fall, as the days gradually get colder, the adult chickens will adjust just fine.

 

[33yardbirds]

Mine go out in the coop at 6 wks regardless. I do have a hanging heat lamp for them until I pull the door to the pen. once they start venturing out side the lamp is off. About 8 wks.