Apply liberally 15 minutes before sun exposure. Reapply: After 40 minutes of swimming or sweating, immediately after towel drying, and at least every 2 hours. 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 spectrum SPF 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-sleeve shirts, pants, hats, and sunglasses. Children under 6 months: Ask a doctor.