The primary means of lessening one’s risk of developing basal cell carcinoma is limiting exposure to sunlight. However, since the majority of an individual’s lifetime exposure to the harmful rays of the sun is acquired during childhood and the latent period between intense exposure to sunlight and the onset of basal cell carcinoma is 20 to 50 years, preventative measures are best begun in one’s youth. The most simple and effective means of avoiding too much sun are limiting outdoor activities to hours when the sun’s rays are less intense (generally before 10 a.m. and after 4 p.m.), wearing long pants, long-sleeved shirts, and a broad-rimmed hat whenever possible, and regularly applying sunscreen with a sun protection factor of at least 15. If one is physically active outdoors, it is important to remember that sunscreen will need to be periodically reapplied, usually about once every one-and-a-half hours.