Sun avoidance: Seeking shade, minimizing outdoor activities between 10 AM and 4 PM (when sun's rays are strongest), and avoiding sunbathing and the use of tanning beds Use of protective clothing: Long-sleeved shirts, pants, and broad-brimmed hats Use of sunscreen: At least sun protection factor (SPF) 30 with broad-spectrum UVA / UVB protection, used as directed (ie, reapplied every 2 hours and after swimming or sweating); should not be used to prolong sun exposure Key Points Squamous cell carcinoma, because of its high frequency of occurrence and highly variable appearance, should be considered in any nonhealing lesion in a sun-exposed area.