Cold Weather

There are a variety of health conditions that can be caused by prolonged exposure to cold temperatures. When combined with wind chill, they can become deadly. Hypothermia, frostbite, trench foot, and chilblains are all conditions that are preventable and have distinct warning signs. Knowing and recognizing the signs and symptoms is important to keep yourself and your coworkers safe. If you or a coworker begins experiencing symptoms from exposure to cold temperatures, it is important to move to a warm location immediately. If symptoms do not improve, or worsen, it may be necessary to seek immediate medical care.

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Protecting Yourself
Cold Stress Health Conditions
Myths About Cold Weather
Additional Resources

Wind Chill

What is Wind Chill?

The wind chill temperature is based on the rate of heat loss from exposed skin caused by wind and cold and gives you an approximation of how cold the air feels on your body. As the wind increases, it removes heat from the body, driving down skin temperature and eventually the internal body temperature.

Oregon OSHA does not have specific cold weather regulations, however there is the general duty clause that states that “each employer shall furnish to each of their employees a place of employment which is free from recognized hazards that are causing or are likely to cause death or serious physical harm to their employees.”

What is the NWS Wind Chill Temperature Index?

The NWS Wind Chill Temperature (WCT) index uses advances in science, technology, and computer modeling to provide an accurate, understandable, and useful formula for calculating the dangers from winter winds and freezing temperatures. The combination of wind and low temperatures in winter can be deadly. The wind chill index helps you determine when dangerous conditions develop that could lead to frostbite or hypothermia. It considers 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 30 degrees occurring with a 25-mph wind gives a wind chill near 16 degrees. This means that your body will lose heat at the same rate as it would if the air temperature were 16 degrees with no wind. Wind chill values near minus 25 degrees mean that frostbite is possible within 15 minutes! The lower the wind chill temperature, the greater you are at risk for developing cold-related health conditions.

National Weather Service's Calculator

Protect Yourself!

Monitor your physical condition and that of your coworkers.
Wear appropriate clothing.
- Wear several layers of loose clothing for insulation.
- Tight clothing reduces blood circulation to the extremities.
Be aware that some clothing may restrict movement, resulting in a hazardous situation.
Protect the ears, face, hands and feet in extremely cold or wet weather.
- Boots should be waterproof and insulated.
- Wear a hat to reduce the loss of body heat from your head.
Move into warm locations during breaks; limit the amount of time outside.
Carry extra socks, gloves, hats, jacket, blankets, a change of clothes and a thermos of hot liquid.
Include chemical hot packs in your first aid kit.
Avoid touching cold metal surfaces with bare skin.
Keep your skin dry.
Stay out of the wind.
Drink fluids since hydration increases the blood's volume, which helps prevent frostbite.
Avoid caffeine and cigarettes.
- Caffeine constricts blood vessels, preventing warming of your extremities.
- Cigarettes shut off the blood flow to your hands.

Cold weather clothing like gloves, hats, and layering

Health Conditions

There are a variety of health conditions that can be caused by prolonged exposure to cold temperatures. When combined with wind chill, they can become deadly. Hypothermia, frostbite, trench foot, and chilblains are all conditions that are preventable and have distinct warning signs.

Hypothermia

A condition in which the body uses up its stored energy and can no longer produce heat. Often occurs after prolonged exposure to cold temperatures.

Early Symptoms	Late Symptoms	First Aid
Shivering Fatigue Loss of coordination Confusion and disorientation	No shivering Blue skin Dilated pupils Slowed pulse and breathing Loss of consciousness	Request immediate medical assistance. Move the victim into a warm room or shelter. Remove wet clothing. Warm the center of their body first—chest, neck, head, and groin—using an electric blanket; or use skin-to-skin contact under loose, dry layers of blankets, clothing, or towels. If conscious, warm beverages may help increase the body temperature. Do not give alcohol. Once temperature has increased keep them dry and wrapped in a warm blanket, including the head and neck. If no pulse, begin CPR.

Frostbite

An injury to the body that is caused by freezing, which most often affects the nose, ears, cheeks, chin, fingers, or toes.

Symptoms	First Aid
Reduced blood flow to hands and feet Numbness Aching Tingling or stinging Bluish or pale, waxy skin	Get into a warm room as soon as possible. Unless necessary, do not walk on frostbitten feet or toes. Immerse the affected area in warm (not hot) water, or warm the affected area using body heat. Do not use a heating pad, fireplace, or radiator for warming. Do not massage the frostbitten area; doing so may cause more damage.

Trench Foot

An injury of the feet resulting from prolonged exposure to wet and cold conditions that can occur at temperatures as high as 60 °F if the feet are constantly wet.

Symptoms	First Aid
Reddening of the skin Numbness Leg cramps Swelling Tingling pain Blisters or ulcers Bleeding under the skin Gangrene (foot may turn dark purple, blue, or gray)	Remove shoes/boots and wet socks. Dry feet. Avoid walking on feet, as this may cause tissue damage.

Chilblains

Ulcers formed by damaged small blood vessels in the skin, caused by the repeated exposure of skin to temperatures just above freezing to as high as 60 °F.

Symptoms	First Aid
Redness Itching Possible blistering Inflammation Possible ulceration in severe cases	Avoid scratching. Slowly warm the skin. Use corticosteroid creams to relieve itching and swelling Keep blisters and ulcers clean and covered.

Myth: You do not need sunscreen in winter.
Fact: We are actually closer to the sun in the Northern hemisphere winter so more radiation is reaching us from the sun. Also, snow cover reflects skin damaging radiation thereby magnifying the danger.

Myth or Fact?

Myth: The body loses most of its heat through the head.
Fact: The body generally loses heat in proportion of exposure. The surface area of the head counts for about 7% of the total body coverage and loses heat at about the same rate as any other 7% of the body that is exposed to the cold.

Myth: Cold air will give you a cold.
Fact: There may be other extenuating circumstances that can lead to a cold but just going outdoors without a coat does not directly increase your change of contracting a cold.