Arrived home this morning to find one dead golden comet and another very lethargic. She will not open her eyes nor eat at this point. No issues till today.. The birds are all outside in the coop separate from our laying hens. Temps here have been cool in North Texas but not what I'd call cold. They are all eating well and up till today were active. Only the two comets seem ill. They have a heat lamp in an open area of the coop to remain warm if they need some additional heat but most, if not all, seem not to need it. Ideas?