We FINALLY got our chicken coop and run ready for our 4-5 week old chicks to move in. My question is: Should they be allowed to use the run right away or should I keep the door to outside closed for a few days? We have 9 babies. The coop part is 6x6 and the run is 12x14 or so. Also- nights for the past couple of days have been in the low 50's. Do they need a heat light? they are currently living in our sunporch. We haven't used the heat lamp for a few days, but I am worried they will be cold outside. thanks for your help.