It's a curious thing, you're walking your dog on a breezy day and you feel nice and cool, then you look at your dog who is panting like it's 93° It took me a few years too long to figure out that wind doesn't cool dogs off. Dogs have fewer sweat glands than we do and cool off primarily through panting.
While wind may cool off the overall air temperature, walking in the sun, even on a windy day, may overheat your dog.
Make sure you give your dog lots of water and check frequently for signs of overheating. Since dogs do have sweat glands in their paws, they can cool off by walking in water. Puppies and older dogs may also have more difficulty regulating their body temps, so they need extra watching
We still do group dog walks in summer, even on hot days, but we carry plenty of water, walk on the shadiest trails around and if it's really hot, we go from one shady spot to the next with plenty of rest.