Winter weather can not only be trying on the mind and soul, it also presents very real dangers to the human body.  Extreme wind chills can be deadly and bring on the outset of frostbite and hypothermia.  Here in Colorado, all residents should be aware of these hazards and be prepared to deal with them. 

In this fourth in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand wind chill and how to protect yourself from frostbite and hypothermia.  

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
ISSUED BY NATIONAL WEATHER SERVICE GOODLAND KS 600 AM MDT THU OCT 23 2008

Extreme wind chill – Potentially life-threatening and often overlooked

The combination of wind and cold temperatures in winter can be deadly.  Winter storms often bring heavy snow to Colorado which results in slick roadways, traffic accidents and stranded travelers.  While the attention of most people is focused on expected snow accumulation before a storm arrives, many ignore the life threatening combination of extreme cold and strong wind which often develops after the storm passes.  Wind chill is a measure of heat loss from the body due to wind and cold air.  Frostbite and hypothermia are two consequences of wind chill.  All three will be discussed today as part of Colorado Winter Weather Preparedness Week.

The wind chill index helps you to determine when dangerous conditions develop that could lead to frostbite or hypothermia.  It takes into account heat loss from the human body to its surroundings during cold and windy weather.  The calculation utilizes wind speed in miles per hour and temperature in degrees Fahrenheit.  For example, a temperature of minus 5 degrees occurring with a 20 mph wind gives a wind chill near minus 30 degrees.  This means that your body will lose heat at the same rate as it would if the air temperature were minus 30 degrees with no wind.  Wind chill values near minus 25 degrees mean that frostbite can occur in as little as 15 minutes.

Frostbite first affects exposed body tissue where blood circulation may be limited, such as fingers and toes, as well as your nose and ears.  To minimize frostbite, make sure all body parts are well covered.  When frostbite starts, feeling is lost in the affected area and the frozen tissue will take on a white or pale appearance.  If you suspect you are experiencing frostbite, hold the frostbitten area closely against warm skin to return blood flow and warmth to the affected area.

Hypothermia is a dangerously low body temperature and is the most common weather killer in winter. When you hear of a hiker or climber, or a hunter or stranded traveler perishing from cold weather exposure, hypothermia was the cause.  Most people are surprised to learn that hypothermia deaths can occur with temperatures between 30 and 50 degrees.  If you or your clothing are wet, then hypothermia becomes even more likely. 

Warning signs of hypothermia include uncontrollable shivering, memory loss, disorientation, slurred speech and drowsiness.  Immediate medical attention should be given to victims suspected of suffering from hypothermia.  If no help is available, the victim should be warmed slowly with warm liquids along with dry clothing and blankets.

The National Weather Service offices in Boulder, Pueblo, Grand Junction and Goodland Kansas will issue wind chill advisories and warnings when a deadly combination of wind and cold air threaten the area.  To learn more about wind chill and to see a wind chill chart, visit the National Weather Service internet site at weather.gov/om/windchill. 

When cold weather threatens Colorado, follow these tips for survival, stay dry, wet clothing results in much faster heat loss from your body.  Wear waterproof insulated boots.  Stay covered, wear mittens or gloves on your hands and a hat to cover your head. At least half of your body heat is lost if your head is not covered.  Dress layered, the trapped air between loose fitting clothing helps to insulate.

Stay informed and have a portable NOAA weather radio all-hazards to keep you up-to-date with the latest forecasts and warnings.  Use wind chill temperatures to guide you in dressing properly for the outdoors.  On very cold days, be smart and minimize your exposure to the outdoors if possible.

David Floyd
Warning Coordination Meteorologist
National Weather Service, Goodland, Kansas

For more information:  Colorado Division of Emergency Preparedness – Winter Weather Preparedness Week