Since Okinawa has a subtropical climate, sunburn is a common problem. To prevent sunburn, use a broad-spectrum sunscreen with an SPF of at least 30 and reapply every two hours or after swimming or sweating. Wear protective clothing such as long-sleeved shirts, wide-brimmed hats and sunglasses. If you do get sunburned, cool the skin with a cold compress, apply aloe vera or a moisturizing cream with anti-inflammatory properties, and make sure you stay hydrated. Seek professional medical help for severe burns.