I have been taking my baby chicks outside all day (its been about 85). The chicks love the coop and run and my hens love to come and look at the baby chicks through the welded wire. MY question is: WITH a heat lamp can the baby chicks be left outside? It will get down to 45 F. There are enclosed boxes and I can put the heat lamp outside the box, but not so much in it (fire hazard). Anyways there are 28 chicks so they can huddle??