The one thing you dont want t do is cook the babies!!! if you keeps the light on when they are at least 5 weeks old in the middle of the hot day that could make them to hot. Oh and by the way to any one whos reading this, did you know that chickens pant! Just like dogs do huh huh huh huh!!! that how it goes. By the way i am am 12 years old. A first time chicken farmer! No pun intended!