I don't take the chance, I have a heat lamp in the cage in the shed as I type for the 3 birds still in it. I found a bird that froze to death and I vowed it will never happen again. What a horrible way to die. So for me I say use the heat lamp when temps get too extreme for the younger birds, sometimes the adults need it too.Yoda, peafowl that are 6-8 months old don't need a heat lamp. I don't use them for anything but chicks starting out, and even then I had one shatter when (I assume) a drop of condensation hit it and there were glass pieces everywhere. Up here any peachicks hatched will be around 3-4 months old when it gets cold since it will be June at the earliest before they even start laying and we get snow as early as early October. In the winter, if I bring them in for any reason I most likely won't be able to put them back out until spring since I don't want to take them from house temps back out to 10 degrees or colder. I do have one staying in the house for the winter, but she hatched on 9/14. 1 month old is too young to leave out in the cold...