Chicks are ideally at 90F for the first few weeks of life. When weather is cooler, they put chemical heat bags in the shipping boxes. I’ve never experienced it,

Chicks are ideally at 90F for the first few weeks of life. When weather is cooler, they put chemical heat bags in the shipping boxes. I’ve never experienced it, but I’m told that during particularly hot times the hatcheries also use cool packs instead. Point being, they are trying their best to equalize the temps and get those birds to their destination as fast as possible. 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.