We have had extreme heat for over a week with the last 4 days being 110 to 118. Our coop has lots of shade and we have water misters and a small wading pool available. We change all the water often to keep it cool.. All of our chickens drink a lot and have been panting heavy all day, every day. They all seem very healthy, they eat well, they scratch and socialize and still have little bursts of running and flapping. I noticed over the last two days that when I go to do a headcount and close the hen house doors, a couple hens seem to be vomiting lots of water while they are picking their place to roost. They don't seem stressed when this happens and I am assuming it is due to heat and lots of water consumption. Is there anything to worry about? Should I be offering electrolytes in their water or doing anything differently? We have 100 degree weather forecasted for at least the next ten days and possibly longer.