One remedy is aloe vera which soothes and heals damaged skin. They recommend applying aloe vera gel to sunburned skin. There are suggestions for different things you can mix with the aloe vera gel too. That’s just one example. There are many other remedies like herbs, essential oils, hydrosols etc.
There are also some great suggestions for staying hydrated during warm weather too. It’s a great article. Click on the Remedies for Sunburn and Summer Heat link to see all of the remedies for sunburn.