This is because the wind strips away the thin layer of warm air above your skin. The stronger the wind, the more heat lost from your body, and the colder it will feel. When the winds are light, it will feel closer to the actual air temperature.
The blue-shaded areas represent the amount of time it takes to get frostbite at the corresponding wind chill temperatures.
You can determine your wind chill temperature using the chart above. Find the value closest to the outside air temperature, then the value closest to the current wind speed. Your wind chill temperature is the value where the imaginary lines drawn from the air temperature and the wind intersect.
The blue-shaded areas in the wind chill chart represent the amount of time it takes to get frostbite at the corresponding wind chill temperatures.
For example, with an air temperature of minus 20 degrees and a wind speed of 15 mph, frostbite can occur in 10 minutes or less.
Besides the wind chill feeling colder than the actual air temperature, it can pose dangerous risks to your health. The colder the wind chill, the higher the risk for developing frostbite or hypothermia.
Hypothermia occurs when your core body temperature, normally around 98.6 degrees, drops below 95 degrees.
The National Weather Service offers these tips to prevent hypothermia:
Dress in layers
Wrap up well when going outside in the cold
Avoid breezes and drafts indoors
Eat nutritious food and wear warm clothes to ward off winter chill
Wear a warm hat in the winter
Eat hot foods and drink warm drinks several times during the day
If you live alone, ask a family member or neighbor to check on you daily
If your body temperature is 96 degrees or less, you feel cold and sluggish or are having trouble thinking clearly, the NWS says to see your doctor immediately or go to the nearest emergency room. "It's better to be overly cautious than to die of a disorder that does not have to be deadly."
Frostbite occurs when body tissue freezes, such as your fingers, toes, ear lobes or the tip of your nose. In order to protect vital organs, your body cuts circulation to your extremities, including your feet, hands and nose, which eventually freeze.
In order to avoid frostbite, the best thing to do is stay inside when it is bitterly cold. If you have to be outside, you should cover every part of your body, including your ears, nose, toes and fingers. You also want to keep your skin dry and stay out of the wind when possible.