• According to the AACR, 1 in every 20 US cancer cases are caused by UV (ultraviolet) radiation.
• According to the Skin Cancer Foundation, UV exposure causes over 85% of all skin cancers; to reduce UV exposure,
  • Seek shade (especially from 10 AM to 4 PM)
  • Avoid indoor tanning.
  • Wear clothes that cover your arms and legs. Wearing a wide-brimmed hat and wrap-around sunglasses also helps cover your body.
  • Apply adequate sunscreen, with an SPF ≥ 15 (ideally ≥ 30), at least 30 min before going outside (even if it's cloudy). Reapply every 2 hours. Also, reapply after swimming or heavy sweating.

Content above copied nearly verbatim from Cancer Tutorial | Sai Chengalvala