I can close the heat off at what age should I do this and for how long
by four weeks of age they can be in the 50s as long as they have a heat lamp to warm up under.
Just watch them and see how they do. With no wind, it is easier to handle the cold.
I am pretty sure that by two months, mine can handle 40s without a heat lamp.
I need to write this stuff down.
I just keep an eye on them, see how they are doing, and adjust things as needed. My summers are usually in the 50s as a HIGH.