I put my two day old chicks and mama hen (we swapped out eggs for chicks while she was broody), in a dog kennel out in the main chicken run. I covered it at night with a blanket and no heat lamp. I live in the California coast and it’s in the high forties at night. The one mistake I did make is...
I was also told to wait two to three weeks, but my hen was super broody, and had been broody several times this year. We only waited one week and she accepted the 2 day old chicks with no problem! Did a bunch of research and made sure we did it in complete darkness and quiet.