I had a chick manage to get on the outside of the chick pen in the chicken yard. It was raining and cold. And since he couldn't find his way back in to snuggle with the others he almost froze. I thought he was dead. What I did was put him in the incubator. It's a few degrees warmer and once he was dry and warm he was fine and is still fine three months later. If your chickies got too cold in transit maybe you could try putting them in the bator and warm them up a little better?