Extreme Cold

• How Does Wind Chill Affect You?
• Cold Injuries
• Wind Chill Hazards and What to Do

What is Wind Chill?

• Anyone who has ever waited at a bus stop or taken a walk on a blustery winter day knows that you feel colder when the wind blows. We call the cooling sensation that is caused by the combined effect of temperature and wind, the wind chill
• On a calm day, our bodies insulate us somewhat from the outside temperature by warming up a thin layer of air close to our skin, known as the boundary layer. When the wind blows, it takes this protective layer away, exposing our skin to the outside air. It takes energy for our bodies to warm up a new layer and, if each layer keeps getting blown away, our skin temperature will drop and we will feel colder
• Wind also makes you feel colder by evaporating any moisture on your skin - a process that draws more heat away from your body. Studies show that when your skin is wet, it loses heat much faster than when it is dry.
• On cold and blustery winter days, listen for the wind chill index in your local weather forecast! Go to Canada.ca/weather.

How Does Wind Chill Affect You?

• Living in a cold country can be hazardous to your health. Each year in Canada, more than 80 people die from over-exposure to the cold, and many more suffer injuries resulting from hypothermia and frostbite. Wind chill can play a major role in such health hazards because it speeds up the rate at which your body loses heat.
• How much heat you lose depends not only on the cooling effects of the cold and the wind chill, but on other factors as well. Good quality clothing with high insulating properties traps air, creating a thicker boundary layer around the body which keeps in the heat. Wet clothing and footwear lose their insulating properties, resulting in body heat loss nearly equal to that of exposed skin. Your body type also determines how quickly you lose heat: people with a tall, slim build become cold much faster than those who are shorter and heavier.
• In addition, we can also gain heat by increasing our metabolism or soaking up the sun. Physical activity, such as walking or skiing, increases our metabolism - which generates more body heat. Age and physical condition also play a part. Elderly people and children have less muscle mass and, as a result, generate less body heat. Sunshine, even on a cold winter day, can also make a difference. Bright sunshine can make you feel as much as 10ºC warmer.
• Over time, our bodies can also adapt to the cold. People who live in a cold climate are often able to withstand cold better than those from warmer climates.

Beating The Chill

• The best way to avoid the hazards of wind chill is to check the weather forecast before going outside and to be prepared by dressing warmly. As a guideline, keep in mind that the risk of frostbite increases rapidly when wind chill values go below -27.
• A simple way to avoid wind chill is to get out of the wind. Environment Canada's wind chill forecasts are based on the wind you would experience on open ground. Taking shelter from the wind can reduce or even eliminate the wind chill factor. However, you would still feel cold from the outside temperature alone.
• A recent survey indicated that 82% of Canadians use wind chill information to decide how to dress before going outside in the winter. Many groups and organizations use the wind chill index to regulate their outdoor activities. Schools use wind chill information to decide whether it is safe for children to go outdoors at recess. Hockey clubs cancel outdoor practices when the wind chill is too cold. People who work outside for a living, such as construction workers and ski-lift operators, are required to take indoor breaks to warm up when the wind chill is very cold.

Cold Injuries

Exposure to the cold can be hazardous or even life-threatening. Your body's extremities, such as the ears, nose, fingers and toes, lose heat the fastest. Exposed skin may freeze, causing frostnip or frostbite. In extreme conditions or after prolonged exposure to the cold, the body core can also lose heat, resulting in hypothermia.

Hypothermia

Being cold over a prolonged period can cause a drop in body temperature (below the normal 37ºC).
Shivering, confusion and loss of muscular control (e.g., difficulty walking) can occur.
Can progress to a life-threatening condition where shivering stops or the person loses consciousness. Cardiac arrest may occur.

What to do:

• Get medical attention immediately.
• Lay the person down and avoid rough handling, particularly if the person is unconscious.
• Get the person indoors.
• Gently remove wet clothing.
• Warm the person gradually and slowly, using available sources of heat.

Frostnip

A mild form of frostbite, where only the skin freezes. Skin appears yellowish or white but feels soft to the touch. Painful tingling or burning sensation.

What to do:

• Do not rub or massage the area.
• Warm the area gradually - use body heat (a warm hand) or warm water. Avoid direct heat which can burn the skin.
• Once the affected area is warm, do not re-expose it to the cold.

Frostbite

A more severe condition, where both the skin and the underlying tissue (fat, muscle, bone) are frozen. Skin appears white and waxy and is hard to the touch.
No sensation - the area is numb.

What to do:

• Frostbite can be serious and can result in amputation. Get medical help!
• Do not rub or massage the area.
• Do not warm the area until you can ensure it will stay warm.
• Warm the area gradually - use body heat, or warm water (40 to 42ºC). Avoid direct heat which can burn the skin.
• Try this!  Turn on a fan. Stand in front of it. You will feel colder because of the wind cooling your skin, but the temperature in the room has not changed. You cannot make the room any colder, no matter how high you turn up the fan. Similarly, no matter how strong the wind blows, the temperature of the air outside does not change. Now dab some water on your skin. Stand in front of the fan again. The wet skin will feel much colder. This demonstrates how important it is to stay dry when outdoors in cold and windy conditions.

Wind Chill Hazards and What to Do

Source: Get Prepared