In terms of sunburn, the most important factor is PREVENTION! Wearing a sunscreen with SPF 30 or higher and reapplying sunscreen every 2 hours, or when you get wet or sweat, can help prevent sun damage. Also, wearing sun protective clothing and hats is a great way to protect from damaging sun rays. Sunburn is a sign of skin damage, and can increase your risk of skin cancer.
If you do get sunburnned, protect you skin from further exposure to the sun, moisturize the skin regularly with a soothing, bland moisturizer, and consider an anti-inflammatory medication by mouth if permitted.
Did you know that some medications can make you more sensitive to the sun (and sun burning)? Antibiotics that can make you more sun sensitive include doxycycline and tetracycline, among others. Keep in mind that NSAIDS (non-steroidal anti-inflammatory medications) such as ibuprofen and naproxen are known to make skin more sensitive.
Just one more reason to protect from the sun!