I kept cherry shrimps outside once. They did well even in 90+F weather but keep out of direct sunlight and off the pavement. It's too hot for that.
Mine's not in direct sunlight, it's in pretty much full shade and mine have been fine in well over 90 degree temps. I was asking about lids/tops for the pond containers. Just trying to keep predatory bugs/nymphs out of my water and the lid I have on there is so solid I think it may be contributing to their color fade.