Hi, My chicks are getting big! Their coop is just about finished and I'm ready to get them out of the house at night. They have been spending the days outside in a run for about a week. We're in San Diego and it's about 58-60 degrees at night here. Would they be alright to sleep in the "cold" like that or should I have a heat lamp out there with them. They have a lot of feathers and are looking like little chickens. They would be in an enclosed coop. Thanks for your help!