Extreme cold
Note
The impacts of extreme cold spells are closely linked to the effects of other factors, such as longer periods of extreme cold and cold waves. For that reason, this page will take a comprehensive approach to addressing the consequences of “extreme cold,” covering the various phenomena associated with cold weather.
Extreme cold has many effects on the health and well-being of the population, as well as on ecosystems.
Health impacts
In addition to increasing the risk of cardiovascular disorders, extreme cold can have other impacts on physical health such as frostbite, chilblains and hypothermia. Cold temperatures also increase inflammation and dry out the mucous membranes of the respiratory system, making the body more vulnerable to infectious diseases.
To avoid the discomfort associated with cold weather, individuals tend to change their behaviour: they spend more time indoors with other people. This increases the risk of developing illnesses and infections such as influenza, pneumonia and bronchitis.
In terms of mental health, cold temperatures can result in isolation and contribute to psychological disorders like anxiety, depression and mood disorders associated with winter, which are caused by the reduced daylight hours.
Key population groups that are particularly vulnerable to extreme cold include:
The elderly
Outdoor workers
People experiencing homelessness
Residents of poorly heated or poorly insulated dwellings
Disadvantaged people and those experiencing energy poverty
Infants and young children
People with pre-existing medical conditions (kidney and heart problems, smoking)
The effects of cold on the body
In cold weather, the body reacts in such a way as to produce heat and redistribute it to the vital organs. It does this by increasing the heart rate and breathing rate and by contracting blood vessels, bronchi and muscles. Extreme cold therefore increases the risk of cardiovascular, respiratory and cerebrovascular disorders up to two weeks after exposure.
This project fine-tuned the development of the weather-based health alert thresholds for several extreme situations, such as extreme cold, so that adaptation measures for the healthcare system can be implemented in Quebec and Canada.
Impacts on agriculture and forestry
Cold temperatures can have many impacts on plants such as bud death, root degradation and trunk bark degradation. The cold hardiness of plants varies from one species to another and depends on the conditions of the cold episode, including:
Its intensity and duration
Its timing
The speed of the temperature drop
The temperatures that preceded it
The changing climate is also engendering risks for crops. Although the frequency and intensity of extreme cold spells is decreasing, other changing climate conditions have disadvantages.
For example, the increase in the frequency of winter thaws will lead to a decrease in the snow cover that protects roots from the cold in winter. Combined with higher temperatures in the fall, this can make plants more vulnerable to cold weather.
Milder winter temperatures will also allow various destructive species to survive the cold season, such as deer, migratory birds and insect pests.
Impacts on heating
Extreme cold is associated with greater electricity consumption, but also the increased use of wood stoves and fireplaces, which can contribute to the deterioration of the air, both indoors and outdoors.
