You can take him outside daily for up to an hour or more but sit him in the grass so he doesn't overheat. A dog crate would have a plastic bottom I believe ? That would heat up way too hot, think of putting your hand on a car that's in the sun and it's comparable to that . Since he's not well he won't have the strength to run off so just set him in the grass. If you can only put him in a dog crate, you would have to create artificial shade on the outside of the crate, like a large fake plant or a piece ot trellis.