I have 13 chicks that are 10 days old, flying in the brooders (split between two). I've already lowered them away from the heat once a few days ago, and already notice them occasionally sleeping at the opposite end of the brooder. I read a lot of recommendations for putting them out at 6 weeks. Can I put them out sooner if I put a heat lamp in the coop? The high is supposed to be 70 this weekend, but then get cold next week with one day forecasted to be 54 / 37.