When your chicks are fully feathered (about six – eight weeks old) and the temperature is warm enough. Typically you set your brooder (the pen used to start your chicks) temperature at 95 degrees for the first week. After that you reduce it 5 degrees per week until the temperature inside your brooder or coop matches the temperature outside. Be careful with your family dog! They might see your chickens as a tasty snack instead of cute, fluffy pets.
What if it’s winter outside? Chickens are very cold hardy if allowed to acclimate to the cold. They develop fluffy down under their hard feathers when exposed to the cold. This helps them stay warm in even subzero temperatures. However, if the chickens aren’t exposed to cold weather slowly, they can’t take it well since they haven’t developed those extra feathers yet. Keeping this in mind, expose your fully feathered chicks to the cold gradually so they can start developing the extra under feathers needed to handle the cold. There is no definite guideline. Keep an eye on them when they are outside. If they are all huddled together in a pile, they are too cold.