I've never had this happen before and i've gotten chicks in colder weather, mine wasn't the only box, 4 came to the PO 2 of the others all dead, one box had about 5 left alive, they weren't pack right all the holes were open and a thin piece of card board around the out side. I pick them up as soon as the PO called, I go to the main PO to get them and I don't wait till they arrive at my PO, if I did they wouldn't be there till tomorrow. I just can't believe there all dead