You've got your sunglasses and sunblock, but there's something else you'll need. Find out what on today's EnvironMinute. The UV Index predicts the intensity of the sun's ultraviolet rays. These are the rays that can cause skin cancer. A scale from zero to ten describes your exposure level.
Higher numbers mean a greater risk of harm.
Factors that determine the UV Index include temperature and cloud thickness. The condition of the ozone layer is also important. A thin ozone layer allows more radiation to reach your skin. The EnvironMinute is produced in cooperation with the National Safety Council and made possible by the Teresa and H. John Heinz III Foundation.