I have a smaller container with water. They like to stand in it too cool off. You can also put a brick in the water. The brick will stay wet and the chickens like to stand on that.My girls are not laying yet, soon- 17 weeks. I have been giving more veggie/ fruits than normal but only as a cool treat in heat of the day. I make popcycles in small Rubbermaid containers with corn or small chopped veggies, frozen watermelon ect. Right now I am worried about the heat effects. Trying to cool them down. I also am adding some high protein game bird starter to their regular starter feed to increase the protein. I do also wet down their run and refill cool water.