I'm curious how they protect the chicks in the mail during shipping when the temperature has been in the low-mid 90s the past few weeks in PA. Even in Maine it hit 90.
Heat is generally the bigger issue - birds that are a few weeks along have a greater problems when it’s too hot out. If it is cold, they will pack together and keep each other warm - it’s actually quite happy to see, as at least with my birds they seem to put aside their issues and look out for each other when they get cold.