The best way to ensure you won't get a scalp sunburn is not to go outside, but that's not so much fun during summertime. Your best options are to wear a hat and apply sunscreen. For individuals with a full head of hair, sunscreen should be applied directly onto the head. Those who are bald can use the sunscreen right on their heads. It's also helpful to use a bald head moisturizer for added protection. Of course, it isn't easy to protect the scalp if one has hair, especially very thin or short hair.