I agree that you should give them plenty of space to get out of the heat. Mine are 4th babies and I'm already beginning to wean them from the light. They don't need it during the heat of the day so I turn it off. They do however still have a "feather duster" (homemade with molted chicken and duck feathers, no need to not be creative) that they can cuddle under if they do need some warmth. Then its back on in the evening. I would suggest the MHP system over the light any day. It mimics the natural instinct of being under a momma hen. (Which is why I have the feather duster). As long as weather permitting, set them up a pen outside on the ground as soon as you can and give them a little more time each day in the grass. This helps build their immune system. Free choice of electrolytes and clean water should be offered 24/7 and no, they will not eat themselves to death.