Bits of the body that get regular sun exposure are, perhaps counterintuitively, less likely to develop melanomas. Your face builds up a tan and a tolerance to UV radiation, so most people don’t get terrible sunburns there. Your back, on the other hand, usually doesn’t get much exposure on a daily basis since work- and school-appropriate clothing covers it up. During a swimsuit-clad trip to the pool or beach, that area gets a ton of exposure that it isn’t used to. Without proper precautions, that can result in a painful, peeling burn. The more sunburns like that someone gets in a lifetime, the higher their risk of melanoma.