If the sunburn is localized, apply full strength apple cider vinegar on the affected skin to obtain relief. Do this by soaking a thin towel in apple cider vinegar and placing it over the burn. Leave it on to help prevent peeling and itching.
If the sunburn covers a large part of the body then try this home remedy recommended by Patricia Bragg in her book called Apple Cider Vinegar-Miracle Health System:
Take a cool bath in which one cup of ACV has been added. After soaking in the bath, gently dry the body and pat ACV directly onto the needed areas. Wait 5 minutes, then pat on aloe vera gel.