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Severe Cold Weather

This page was reviewed or revised on Wednesday, November 09, 2011 9:34 AM

Severe Cold Weather

When winter temperatures drop well below the average for that time of year these are called Extreme Cold Events.

The Wind Chill Index is what the temperature "feels like" during cold weather when you combine the air temperature and wind speed. As the wind speed increases, it draws heat from the body, reduces skin temperature, and lowers the inside body temperature. The mix of low temperature and high wind speed means the risk for frostbite, hypothermia and other cold-weather injuries increases.

During extreme cold weather, everyone is at risk. Some groups are at a higher risk. They include:

• infants
• seniors
• homeless
• people who work, or are active, outside
• people living in poorly-insulated homes, without heat or power.

The best way to get ready for severe cold weather is to dress warmly, in layers, and stay dry. This includes winter hats, scarves, gloves or mittens, water resistant coats and boots. See Table 1 for more information.

Table 1: Health concerns and what you can do at various levels of the wind chill index.

Wind Chill	Description	Health Concern	What to do
0 to -9	Low	Slight increase in discomfort.	Dress warmly, with the outside temperature in mind.
-10 to -24	Moderate	Exposed skin feels cold. Risk of hypothermia if outside for long periods without protection.	Dress in layers of warm clothing, with an outer layer that is wind resistant. Wear a hat, mittens and scarf. Keep active if outdoors.
-25 to -44	Cold	Risk of frostbite. Risk of hypothermia if outside for long periods without protection.	Check face, fingers, toes, ears and nose for numbness and whiteness. Dress as above. Cover all exposed skin, particularly face and hands. Keep active if outdoors.
-45 to -59	Extreme	Frostbite may occur in minutes if skin exposed. Serious risk of hypothermia if outside for long periods.	Check face, fingers, toes, ears and nose for numbness and whiteness. Be careful. Dress as above. Be ready to cancel outdoor activities. Keep active if you must be outdoors.
-60 and colder	Extreme	DANGER! Conditions are hazardous. Frostbite may occur in less than 2 minutes.	Stay indoors.

Cold weather injuries

Exposure to the cold can be hazardous, or even life-threatening. Body parts, such as the ears, nose, fingers and toes, lose heat the fastest. See Table 2 for more information about cold weather injuries.

Table 2: Cold weather injuries, symptoms and treatment.

Frostnip Symptoms: a mild form of frostbite; 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 or warm water (40°C-42°C), avoid direct heat that can burn the skin once the affected area is warm, do not go back into the cold.

Frostbite Symptoms: a more severe condition, where both the skin and the underlying tissue are frozen skin appears white and waxy, and is hard to 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 ensure it will stay warm warm the area gradually; use body heat, or warm water (40°C-42°C), avoid direct heat that can burn the skin.

Hypothermia Symptoms: feeling cold over a prolonged period of time can cause body temperature to drop below normal (37°C) shivering, confusion and loss of muscular control can occur can be a life-threatening condition when shivering stops, person loses consciousness and cardiac arrest may occur. What to do: get immediate medical help gently lay the person down, especially if unconscious move the person indoors and gently remove wet clothing warm the person gradually, using any available source of heat.

How to avoid cold weather injury

1. Listen to the Environment Canada weather forecast – listen for weather warnings.

2. Plan ahead – limit your time outdoors during very cold wind chills.

3. Dress warmly – cover exposed skin; dress in layers, with an outer layer that is wind resistant.

4. Seek shelter – get out of the wind.

5. Stay dry – wet clothing chills the body; remove outer layers or open your coat if sweating.

6. Keep active – keep moving to keep warm.

7. Know your limits – infants, children, elderly, those with circulation problems are more at risk.

Source: Environment Canada wind chill information website:

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For more information about severe cold weather, call Environmental Health and Prevention Services at 519 383-8331 ext. 3601, or toll free at 1-800-667-1839.