The wind chills

Photo | depositphotos.com

In the winter, the wind chills you and me. That same movement of air that we long for on a summer afternoon is an unwanted visitor in the cold heart of winter. There’s a big difference between a kid waiting at a bus stop when it’s 35 degrees and calm versus 35 degrees and windy.

Wind chill is how your body feels when the air is cold and the wind blows. It’s based on research of how fast our skin loses heat, as wind carries it away. When our bodies can’t generate enough heat to keep our overall temperature near normal, body temperature begins to fall. That’s the chill brought on by the breath of wind on your neck, hands, face or body if you are underdressed.

Wind chill — also called wind chill index or wind chill factor — comes from a formula. Search online for a wind chill calculator or wind chill chart to get the value. There are many formulae that produce the number, but the end result of most of them is in the same range.

There has been a wind chill since our earliest ancestors roamed the planet, but it was not put into a formula until the 1940s. It became more used in weather broadcasts and reports in the last half century, as we’ve learned the dangers of frostbite and hypothermia. 

Just like running a fever can be bad for you, if your body temperature falls by a few degrees, that can be bad, too. 

Wind chill is a big deal. If it’s 40 degrees with a 15 mph wind, your body loses heat to make you feel like it’s 32 degrees. If it were 30 degrees with that same 15 mph wind, you would feel like it’s 19 degrees. Frostbite and hypothermia would happen more quickly. If your skin is wet from rain, snow or sweat, there’s an even faster loss of body heat from evaporation.

Can a temperature above freezing with a wind chill below freezing freeze your plumbing, or the water in your dog’s bowl? No. Wind chill, used in weather forecasts, only applies to exposed human flesh. That means your cat and dog feel a chill, but it’s not the same chill you feel, because they have fur coats. I’m sure if they could talk, they would convince you on a cold day they need to be inside by a warm plate of food. They would probably sell you that on any day.

While air temperature is slow to change, if the winds gust, the wind chill falls quickly and then rises when the gust dies down. It fluctuates with wind gusts. Wind removes heat from any object fast, but wind chill cannot lower the temperature of an inanimate object below the actual air temperature.

Avoid wind chill on a windy, cold day simply by limiting the amount of your skin exposed to the air and by not allowing your clothing or skin to get damp or wet.