For many people, winter means dry skin and high heating bills. But if you find yourself outdoors in the right conditions, it can also mean frostbite. Frostbite occurs when the skin and the tissue beneath it freezes, causing pain, loss of sensation, or worse. It's easier to contract than you may think, even if you don't live in the Siberian tundra. To see if frostbite poses a threat where you live, check out this chart spotted by Digg.

The chart, developed by Pooja Gandhi and Adam Crahen using National Weather Service data, looks at three factors: wind speed, air temperature, and time spent outdoors. You can hover your cursor over data-points on the table to see how long you'd need to be exposed to certain wind chills for your skin tissue to freeze. If the wind chill is -22°F, for example (10°F air temperature with 5 mph winds), it would take 31 minutes of being outside before frostbite sets in. You can also look at the time scale above the chart to calculate it a different way. If you bring your cursor to the 40-minute mark, a window will tell that frostbite becomes a risk after exposure to -17°F wind chill for that amount of time. You can play with the interactive table at Tableau Public.

Chart of cold weather conditions.
Adam Crahen, Pooja Gandhi

If you can't avoid being outside in extreme wind and cold, there are a few steps you can take to keep your skin protected. Wear lots of layers, including multiple socks, and wrap your face with a scarf or face mask before venturing into the cold. Also, remember to stay hydrated. According to the American Academy of Dermatology, drinking at least one glass of water before going outside decreases your risk of contracting frostbite.

[h/t Digg]