We have 8 ISA Brown chicks,that are 4 weeks old. They have been in a 50 gallon bin indoors with a heat lamp, but were starting to look crowded, so I built them a larger pen in the garage (just till the coop is done). I am wondering, can I move them directly to the garage (still using the heat lamp), or will that be too much of a "shock"? The temperatures are still pretty chilly (30-40's at night, maybe 50-60 during day), will it be too cold for them, even with a heat lamp? Should I transition them more slowly- maybe bring them in at night? They do seem pretty well feathered, all but their heads.