While some dogs will wear a hat with no problems, I would have to guess that most dogs do not like to have anything on their heads. It’s just not natural. But humans being what they are, will always find some fun in dressing up their dogs whether the dog likes it or not!
Dog hats come in all shapes and sizes. You can get a simple visor, or beachtop visor for outdoor summer wear. If your dog is into western wear, you can get a Cowboy (or should I say Cowdog) hat and if he fancies himself to be English, you can buy a wool texture London dog hat, if your dog is religious you can even get a yarmulke. For those bad weather days, you can even get a rain hat and boots to match.
As with any item you are going to put on or around your dog, you must consider safety first. Make sure your dog hats do not have any loose parts that can get caught and potentially choke your dog. Inspect the fastening mechanism to make sure that it will break free if it does get caught on something. It’s a good idea to remove the hat from the dog if he is going to be left unattended.