This post originally appeared on Details.com.
It's winter, the sun is MIA, and you can't remember the last time you weren't wearing a parka. So do you really need to lotion up? In a word, yes.
But since "because-I-said-so" arguments only hold so much weight, we're proving it with the top six reasons you should be wearing sunscreen right now.
1. The Earth is closest to the sun in winter. Contrary to popular opinion, the Earth is actually the closest to the sun in the winter and the farthest from it in the summer, says Robert Guida, M.D., a board-certified plastic surgeon in New York City. (FYI, we checked with the Library of Congress to make sure he was right.)
2. The ozone layer is at its thinnest. You know that the ozone layer is good and that ozone depletion is bad, but do you know why? The ozone acts like the Earth's sun shield, absorbing harmful UVB rays before they near the ground. Problem is, the layer is at its thinnest in the winter (according to the National Science Foundation Polar Programs UV Monitoring Network).
3. Sun reflects off snow and ice. Snow and ice might as well come with UV warnings. They can reflect up to 80 percent of UV rays, which not only cause skin cancer but are also the source of about 90 percent of all wrinkles, according to the U.S. Environmental Protection Agency. If that weren't bad enough, those rays can hit your skin not once but twice, according to the Skin Cancer Foundation.
4. You can burn from the wind and sun. Windburn and sunburn are one dynamic (and evil) duo. So when freezing temps and biting winds leave your skin dry, agitated, and pretty much in the fetal position, UV rays have a clear shot at your skin, Guida says. Way to kick you when you're down.
5. The higher the altitude, the more sun exposure you get. Attention, winter-sport enthusiasts: The higher the slopes, the higher your sun exposure. In one University of Canterbury study, skiers at an altitude of two kilometers (that's about 6,562 feet for all of the metric system-phobes out there) were exposed to UV rays that were up to 30 percent greater than when they were at a lower site. UV-radiation exposure increases about 5 percent with every 1,000 feet above sea level.
6. Sunscreen blocks the most rays. Sun rays have a way of working their way through about everything — except freshly smeared sunblock, of course. In fact, about 80 percent of rays pass through clouds. Meanwhile, a white cotton shirt has about an SPF value of seven, according to the Skin Cancer Foundation.
So, this UV-soaked (albeit dreary) winter, check your complaints at the medicine cabinet and put that sunscreen to good use. And while you're at it, check out these six common sun-damage myths.
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