I did keep chicks in my garage when it was chilly this fall, like in October, with an Ecoglow, but they were older and had some feathers. They did fine and slept under it for a while; when they stopped sleeping under it I took it out. The recommendation is to have the ambient temperature 50 degrees or more. Right now, though, I'm not keeping little chicks in the garage with their sole heat source the Eco. Those chicks have a broody hen and are doing great. The ones with the Eco are in the house, and they use it at night when the house is cooler.