Cindie Allen-Stewart shares this remedy on Facebook that she learned from her mother-in-law:
First, buy you some Menthol foam shaving cream. It has to be the foam and it has to have menthol in it. We found Gillette shaving cream on Amazon since we had problems finding menthol foam in stores. We ended up buying 6 cans of it, but it works out because we live in Texas and sunburns happen a lot. (Plus, we have given a couple cans to friends.)
Next, apply the shaving cream on the burn. It may seem like it's a strange shaving ritual, but trust me! Don't rub it in, just let it sit on your skin. It will start bringing all that heat out (you'll be able to feel it). You may feel like you are itchy too, but that's a good thing! Itching means healing.
Then, after about 30 minutes, the shaving cream will seem like it has dissolved in spots. It will seem like it's not as moist and a little dried out. You will feel as if you're becoming a little cold, at least on the sunburned part of your body. THAT IS A GOOD SIGN!
Next, rinse it off in a lukewarm or cool shower or bath. It's just to get the residue off.
Finally, if you still need it, do it again the next day. Usually after that second treatment, the sunburn disappears.
And, of course, your safest bet is to always wear sunscreen - and reapply. Then you won't have to worry about remedies in the first place!