I used a Momma Heating Pad, and brooded my chicks outside from the day they arrived.
From my thread:
https://www.backyardchickens.com/threads/fuzzis-chicken-journal.1550586/post-26587205 Making MHP
https://www.backyardchickens.com/threads/fuzzis-chicken-journal.1550586/post-26589783 Doing...