My birds have access to shade all day as a result of a half solid wall in my aviary. If you don't have one, I would set one up using shade cloth. On really hot days, I go into the aviary and mist them with water every 2 hours or so. I also put out a little dish for them to splash about in if they want to. I take this dish away at the end of the day as I don't want them drinking from it once they have bathed in it. When I am talking about hot days, I do it any day when I see them sitting with their wings out off their body. I try to make sure they are never so hot in the aviary that they pant. I have not lost any due to heat yet.