
I have 5 cocker spaniels, dogs are clever when it comes to keeping cool. They will find a spot in the shade, or like my lot, they lie in my hall on the stone flooring, bellies to the floor back legs out straight, just make sure he's never locked in anywhere hot without water, like a cage or car.
I'm lucky enough to have an air-conditioning unit in my kitchen, so the dogs tend to stay indoors during the hottest part of the day!
He'll be fine!
Forgot to say, as I don't show my dogs, I tend to keep their fur quite short during the summer, not clipped as they do need their fur to protect their skin from the sun, to keep them cool and to avoid all the sticky buds and twigs they are likely to pick up.