New chicken owner needs help please. I have seven 4 week old chicks and just noticed one that is very lethargic, and can barely move. Has trouble walking. Doesn't want to stand up. I cleaned her butt and she immediately had watery poop. She is not peeping but has eyes open. After I cleaned her up and after her poop she did peep a little and drank some water. She is on medicated chick feed and has been vaccinated for Marek's disease. What do I need to do if anything? She is my Australorp I think. Any help would be appreciated. Thank you! (By the way, it is extremely hot around here now...90s/100s. I am keeping them in a storage shed out in the backyard. They are in a baby pool with cardboard walls and pine shavings on floor. I've put plastic netting over the top to let in air. There is a window that I keep open with a fan in it. I just recently added another fan for more air circulation. Neither one is pointed directly at the chicks but blows over them. There is a themometer in the shed and at night it stays in the upper 80s but can get close to 100 during the day.) Again any advice appreciated!!