NASA's Observatorium--Wind Chill: Cold-Weather Dangers

NASA's Observatorium Wind Chill

Cold-Weather Dangers

Let's face it, the weather strongly influences how we plan our day and often what we wear! If it is raining, we carry an umbrella and some outdoor activities may be cancelled. If it's cold and snowing, we dress in extra layers to keep warm and dry. Temperature alone may not provide enough information, though, to help us make good decisions about what to wear or whether to cancel outdoor activities. If there is a strong wind blowing on a cold winter's day, we will feel colder than if there is no wind at all. Based on temperature and wind speed, wind chill is a good indicator of how cold we feel outside and allows us to make better decisions to help avoid cold-weather dangers.

Prevention is always the key! To protect yourself from any cold-weather danger, always dress appropriately. If your local meteorologist says to expect an extremely low Wind Chill Index, don't go outside in shorts! Be careful to remove wet clothing quickly and exchange it for dry garments. Protect your extremities! Fingers, noses, toes, and ears are usually the most susceptible areas to cold-weather injuries. Wear gloves, warm socks that will not cause excessive sweating, and a hat or earmuffs.

So what are these cold-weather dangers? One of them is hypothermia. This is a condition where the core body temperature decreases to a level at which normal muscle and brain functions are impaired. Any prolonged exposure to temperatures less than 98.6 degrees can be linked to hypothermia! Here are some of the conditions that can lead to hypothermia:

Cold temperatures
Wetness
Improper dress/equipment
Alcohol intake
Poor food intake

The severity of hypothermia can vary, depending on how low the core body temperature gets. There are specific signs and symptoms to look for. The condition worsens as the core body temperature lowers.

Mild Hypothermia (core body temperature ranges from 99-95 degrees Fahrenheit):

Involuntary shivering
Inability to perform complex motor functions (such as skiing)

Moderate Hypothermia (core body temperature ranges from 95-90 degrees Fahrenheit):

Slurred speech
Violent shivering
Dazed consciousness
Irrational behavior (for example, the person may begin undressing and is unaware of being cold)
Loss of fine motor coordination

Severe Hypothermia (core body temperature ranges from 90-75 degrees Fahrenheit):

Pupils are dilated
Skin is pale
Pulse rate decreases
Muscle rigidity develops
Shivering occurs in waves, it is violent and then pauses; the pauses eventually grow longer and longer until shivering ceases
Person falls to the ground and cannot walk; may curl into a fetal position to conserve heat
Person loses consciousness, heartbeat and respiration are erratic
Cardiac and respiratory failure, then death

It is important to be able to recognize the symptoms of hypothermia before it is too late. To determine whether someone is suffering from hypothermia, ask the person questions that require higher reasoning skills. For example, someone who is hypothermic will probably be unable to count backward by sixes from 100. Shivering that can be stopped voluntarily is probably an indication of mild hypothermia. If you suspect severe hypothermia and the person is curled into the fetal position, pull back on one arm. If the arm curls back up, the person is still alive, but in need of immediate medical treatment.

Treating Hypothermia
Frostnip and Frostbite

*Disclaimer: The Observatorium assumes no responsibility for the accuracy of the information presented here. The Observatorium does not assume responsibility for any consequences, medical or otherwise, resulting from the use or application of this information. The information presented here is intended for educational purposes only; there is no substitute for proper medical or survival training.

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