Going outside? Check the UV index

Getting out in the sun can be good for you. It provides vitamin D to keep your bones healthy. It also helps prevent or defeat seasonal affective disorder, a form of depression.

But too much exposure to the sun's ultraviolet (UV) rays damages the skin, eyes and immune system. It also leads to melanoma, a deadly form of skin cancer.

The strength of UV rays varies with the time of day, season, latitude and altitude. Clouds, water, sand, concrete and snow reflect UV rays and increase damaging exposure.

Checking the local UV index before going outdoors helps you take action to protect yourself from too much sun. Possible UV damage is reported on a scale of 1 to 15.

• At 2 or below, you can stay outside without needing sun protection.
• Between 3 and 7, you should protect your skin with sunscreen, a shirt and a hat. You should also protect your eyes with UV-absorbant sunglasses and try to stay in the shade at midday.
• At 8 and above, you need extra protection from UV rays. Wearing sunscreen, shirt, hat and sunglasses becomes a must. You also need stay out of the sun and stay in the shade or indoors.

The Environmental Protection Agency offers UV index forecasts by zip code or city and state.

Related Links

Environmental Protection Agency: UV index forecast

Sunglasses: Style + protection

Apply sunscreen the right way

Catching melanoma early: Carrie's story

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First published: 06/30/2004
Last updated: 07/03/2006

Reviewed by: Paul Kleeberg, MD, medical director, Allina.com