Directions For sunscreen use: apply liberally and evenly 15 minutes before sun exposure reapply at least every 2 hours use a water-resistant sunscreen if swimming or sweating children under 6 months of age: Ask a doctor Sun Protection Measures. Spending time in the sun increases your risk of skin cancer and early skin aging. To decrease this risk, regularly use a sunscreen with a broad specrum SPF value of 15 or higher and other sun protection measures including: limit time in the sun, especially from 10 a.m.-2 p.m. wear long-sleeved shirts, pants, hats, and sunglasses