Daily Archives: March 3, 2011

What Is Wind Chill? How Do I Recognize Frostbite?

Published March 3, 2011

A Hubbub explainer

Jose Meledes was all bundled up walking by the Public Garden in this 2004 file photo.

Jose Meledes was all bundled up walking by the Public Garden in this 2004 file photo. (Chitose Suzuki/AP)

Unless you’re living under a rock — actually, even if you’re living under a rock — you know how cold it is. While the temps reached the balmy teens this morning, the wind chill was 10 below zero. So cold my fillings were throbbing.

I realized I don’t totally understand wind chill, so I called a couple of meteorologists: Glenn Field, a National Weather Service meteorologist in Taunton; and Henry Margusity, an AccuWeather meteorologist in State College, Penn., who hosts the Meteorological Madness blog.


What is wind chill?

The Wind Chill Factor measures the apparent temperature — that is, what it feels like outside, not what the mercury on the thermometer shows. Wind takes heat away from the body.

Put another way, Field says: “It’s a relative scale of how long it takes to achieve frostbite.”

How is wind chill measured?

Depends who you ask. For decades, government agencies and TV stations used the standard developed by the National Weather Service. Years ago, AccuWeather invented its own, competing index: the “RealFeel” temperature.

Field, at the NWS, said wind chill is measured by a combination of science and computer modeling:

“It calculates the wind speed at an average height of five feet, which is the typical height of an adult human face, and it’s actually based on something called the Human Face Model. It incorporates all kinds of complicated things like heat transfer theory, the heat loss from the body, and it’s at a walking speed of about three miles an hour.”

[pullquote]If the actual temperature were -15, a wind speed of 10 MPH would produce a wind chill of -35. It would take 30 minutes of unprotected exposure to lead to frostbite.[/pullquote]

For example, if the actual temperature were 15 below zero, a wind speed of only 10 miles per hour would produce a wind chill of 35 below zero. That means it would take only about 30 minutes of unprotected exposure to lead to frostbite.

With 20 MPH winds at the same temperature, wind chill would fall to 42 below 0. In that scenario, a person can get frostbite after only 10 minutes of exposure. Keep this in mind if you walk to work with part of your face exposed.

Over at AccuWeather, Margusity says the RealFeel index takes into account other conditions that yield a more realistic number for humans. AccuWeather takes into account sunshine and humidity, among other factors.

A scene from the film "A Christmas Story," in which a boy's frozen tongue is stuck to a pole.

Don't do this. (Christmas Tree Films)

Field says the NWS overhauled the wind chill index about eight years ago. “You may recall some wind chill indices of 40 below, 50 below a long time ago,” Field says. “New research showed that that was overdone.”

When does the government issue wind chill advisories and warnings?

The NWS issues an advisory if the wind chill is expected to be 15-24 below zero. A warning is triggered if the wind chill is expected to be 25 below zero or colder.

How do I recognize frostbite?

Sometimes you wonder whether you have frostbite or you’re just really cold. Field says these are the tell-tale frostbite symptoms:

  • Loss of feeling in fingers, toes, ear lobes, nose
  • Pale appearance
  • Blue coloring

Prolonged frostbite turns into hypothermia, which is life-threatening. The symptoms of hypothermia are:

  • Uncontrollable shivering
  • Memory loss
  • Disorientation
  • Exhaustion
  • Incoherence
  • Body temperature of 95 degrees or less

How do I help someone with hypothermia?

If someone has hypothermia, resist your instinct to warm up the person quickly. Cold blood could flow to the heart and cause heart failure.

  • Call 911.
  • Warm up the person slowly, starting with the body’s core.
  • Get the person in dry clothing.
  • Cover the head and neck with a warm blanket.
  • Do not provide hot beverages or food. Start with warm broth.

Does wind chill affect cars, machines, pipes?

No. Your pipes are no more likely to freeze, your car no less likely to start, if the wind chill is cold.

What is the grammatically correct way to refer to wind chill?

Wow, you’re getting nerdy. Since you asked, I recall Washington Post copy editor Bill Walsh griping about people who incorrectly say “5 degrees, or minus-25 with wind chill” when they should be saying, simply, “minus-25 wind chill” — no “with.”

So, NWS meteorologist Glenn Field, how do you say it?

“Oh, wow. Well, I would say the actual temperature is 7 below 0, with a wind chill of 20 below zero.”

There you have it.

Reporter Succumbs To MSPCA Press Release

Published March 3, 2011

I tried really hard not to do this.

The press releases from MSPCA, the animal advocacy organization, are so cute, so utterly ridiculous, that it’s tempting to post them in entirety, even without a news peg. There was the puppy hit by a snowplow. There was the cat caught in a mouse trap. There were the pigs who ate fruit salad. Each time, I resisted.

Today, the MSPCA sent out this headline:


I still resisted! But then I received this urgent follow-up…

FYI – Unfortunately the baby Guinea Pigs could not make it in today for photos due to the low temperature.

…and I lost it. So, folks, help an animal in need and adopt one of 22 baby guinea pigs recently surrendered by a Cape Cod resident.

You might say I’ve become the MSPCA’s guinea pig.

Thursday Morning: Levine Jobless; Jobless Rate Steady

Published March 3, 2011

Good morning! It’s bitterly cold out there — wind chill of 10 below. Bundle up.

The U.S. Supreme Court ruled in favor of free speech but against decency in Snyder v. Phelps (no relation), a case that Mass. Attorney General Martha Coakley had weighed in on. The court ruled protestors could picket military funerals. In a statement after the decision, Coakley said: “We respect the First Amendment rights of our citizens, but we also believe that, consistent with those principles, families have rights to honor their loved ones free from disruptive and harmful protests.”

First we learned he was out for the season — now James Levine is out for good come September. The celebrated BSO maestro has suffered from debilitating back problems. It’s a huge loss for Boston cultcha.

The Mass. unemployment rate held steady last month, at 8.3 percent. That’s still lower than the national jobless rate. The state added 5,600 jobs in January.

WBUR’s Bob Oakes interviewed the departing head of Genzyme, the second-largest biotech firm in Mass. The company was (finally) sold to French drugmaker Sanofi-Aventis after a long courtship. Henri Termeer says the company is in good hands.