Swollen feet, due to sunburn?

Possible: Try taking an antiinflammatory and keeping the feet elevated when possible. Aloe on the skin is a good idea as well.

Yes: It is quite common to swell after sunburn feet. Most forget to put sunblock on their feet. Elevate and if have problems see podiatrist.

Drink water.: So a bad sunburn can be very uncomfortable. But the real worry is that if there are open wounds they can become infected and then a real pain. So one of the most important things to do is to hydrate. Drinking water may not be enough. Canned chicken noodle soup is loaded with salt and will help you rehydrate but may worsen the swelling . Try both.