My chicks are 3 weeks old and I want to move them out of my basement into the chicken coop. It is a walk in 34 sq. feet. (New York state) How does one go about keeping it warm enough for them at night? I can hang the heat lamps but is that sufficient of should the overal temp of the coop be 80-85 ish? Also, how high can they fly/jump at this point so I don't have them hitting heating? Thank you!