The ideal summer vacation is sure to include lots of fun, sunny days. To enjoy them properly, it’s important to use sunscreen correctly to avoid damaging the skin’s DNA. Antony Young, leader of a research group at King’s College London, says one of the most common sunscreen mistakes is applying too little, which could mean a reduction of up to 40% of expected protection. Researchers demonstrated that five consecutive days of high exposure to ultraviolet (UV) rays using the right sunblock could do less damage to the skin than a single day of low exposure without a sunblock. The same researchers recommend applying a layer of at least 2 mg per square centimeter of skin and using sunblock with a higher SPF than necessary to counteract the consequences of incorrect use.