our 6 chicks are around 4-5 weeks old & they are getting so big i hate putting them back in their brooder box [3'x4']. we live in SD & the night temps are around 62ish & are wondering if we can move them to the wired in & now secure run? i was thinking of leaving their box/brooder in there on its side to get cozy in as well as a heat lamp... is that cool? too soon? thanks.