We didn't keep or day olds in the house, but we did run an extension cord out to the coop to run the heat lamp. We had 60 chicks, and we only lost 2, and that was in the first week. One got the splayed legs and got too weak, the other one, it was like a runt. This was our first time ever with chickens. On the other side, the guy who rents our land for cattle used to raise chickens for eggs, and he said we wouldn't get eggs during the winter from our hens. Well, we proved him wrong because we had a light on a timer and we got lots of eggs. The only reason we didn't keep the day olds in the house, well, we have 3 dogs, 2 cats and 5 kids, and we just didn't have the room for them inside to keep them. They did fine outside in the coop, but than again it was in My when we got them.