To treat sunburn, use an anti-inflammatory agent. You can also use a cool, damp cloth with skim milk and rest it on the burned spots or bathe with tepid water and avoid soap on the affected area. For more information, check out http://www.wikihow.com/Treat-a-Sunburn.
The best way to treat sunburn i have found believe it or not doesmt matter it works. That is get a spray can at walmart of coppertone spf30 sunblock. Spray it on before bed sometime. Next morning after cool shower spray it on again and headout in sun or whatever for day. By end of day stinging clears right up. Still slight red but no pain. Next day do it again till clears up. then put on suntan lotion and mist sunblock over it every day im in sun all day. damn im tan