Cold weather can be hazardous to health, and each year Canadians suffer injuries and die from exposure to the cold. Local municipalities have a role to play in establishing appropriate parameters for warming centres in order to protect the health and well-being of residents and visitors.
Extreme cold events put everyone at risk, but health risks are greatest for:
- People experiencing homelessness.
- Deaths caused by hypothermia occur thirteen times more often among the homeless than among the general population.
- People experiencing homelessness are likely among the groups most vulnerable to cold effects, in addition to people who live in marginal housing.
- The average lifespan of someone experiencing homelessness is about 17.5 years shorter than the general population, and most deaths occur in conditions of varying intensity of cold stress.
- People living in homes that are poorly insulated (no heat/power).
- Outdoor workers and winter sports enthusiasts.
- People with certain medical conditions such as diabetes or taking certain medications.
- Infants (under 1 year) and older adults (65 years or older).
Cold Weather Warnings
Hastings Prince Edward Public Health publishes the following cold weather notices to the public.
| Cold Weather Health Warning | Cold Weather Health Emergency |
| Temp: -25°C or lower OR WC: -28°C or colder (Env. Canada) | Temp: -35°C or lower OR WC: -55°C or colder OR Cold Weather Warning issued and contributing factors |
Health Complications
Cold temperatures have three primary affects on the body: windburn, frostbite and hypothermia.
- Windburn: Occurs when cold wind removes the top layer of oil from the skin causing excessive dryness, redness, soreness and itchiness.
- Frostbite: When the temperature drops below 0°C, blood vessels close to the skin constrict to protect the core body temperature. When the body is exposed to the cold for a long period of time, blood flow to hands, feet, nose and ears can be restricted significantly. Poor circulation and extreme cold can lead to frostbite. Frostbite can be mild or severe.
- Hypothermia: Occurs when your body temperature drops; it happens in three stages. A normal body temperature is 37°C.
- Stage 1: When body temperatures drop by 1°C or 2°C shivering starts, goose bumps appear on skin, and hands become numb. Breath can become quick and shallow, and the individual may feel tired and/or sick to their stomach. The individual may also experience a warm sensation, which means the body is entering stage 2 of hypothermia.
- Stage 2: When body temperature has dropped by 2°C to 4°C and shivering is strong. Muscles are uncoordinated, and movements are slow and laboured. There may be mild confusion, skin may become pale, and lips, ears, fingers, and toes may turn blue.
- Stage 3: When body temperature drops below 32°C, the shivering will stop but the person will have trouble speaking, thinking, and walking. The individual may even develop amnesia. When the body temperature drops below minus 30°C, exposed skin becomes blue and puffy, it will be hard to move muscles and behaviour becomes irrational. The heart may be beating quickly but pulse and breathing will decrease. At this stage the person is at risk of dying.
- Stage 1: When body temperatures drop by 1°C or 2°C shivering starts, goose bumps appear on skin, and hands become numb. Breath can become quick and shallow, and the individual may feel tired and/or sick to their stomach. The individual may also experience a warm sensation, which means the body is entering stage 2 of hypothermia.
Cold temperatures can also have secondary affects on the body, in particular with stress on the cardiovascular system.
- People are most likely to suffer from cardiovascular (heart) related deaths (ischemic heart disease, acute myocardial infarction) for every 5°C decrease of daily mean temperature.
- The effect of the cold on people’s bodies has been found to last over several days, compared to effects of heat, which are no longer detectable after the day of exposure.
- In cold seasons, each 5°C decrease in daily temperatures is associated with a 3% increase in nonaccidental deaths. The increase in non-accidental deaths persisted over 7 days following the temperature decrease.
- This information implies that weather patterns and corresponding impacts on health allow for more proactive interventions in order to prevent deaths related to cold, than compared to heat. This strengthens the argument that cold related mortality merits additional attention from a public health perspective.
Windchill does not result in a better prediction of mortality compared to air temperature, suggesting that cold advisories are best based off of temperature alone. Warnings related to windchill reflect impact on personal comfort rather than risk to health.
Protect Yourself
- Stay in heated buildings as much as possible (homes or public buildings, e.g. library or mall).
- Drink warm fluids, but avoid caffeinated or alcoholic beverages, as they cause your body to lose heat more rapidly.
- If going outside, dress in layers with a wind resistant outer layer and cover all exposed skin. Wear sunglasses, lip balm and sunscreen (face mask and goggles if windburn is a concern).
- Avoid strenuous exercise outdoors, but stay moving (especially hands and feet) to keep blood flowing and maintain body heat.
- Be up-to-date on the weather conditions, wind chill alerts and extreme weather warnings before going outdoors or travelling.
- Have an alternate source of heat at home: wood or propane furnace, or kerosene heater (must be approved for indoor use), generator with several days’ worth of fuel (generators produce toxic gases such as carbon monoxide so should only be used outdoors), electric space heaters with automatic shut-off and non-glowing elements and/or blankets.
Resources
- Extreme Cold – Health Canada
- Extreme Cold – Ministry of Health and Long-Term Care
