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British Columbia heatwave

Don MacKinnon / AFP

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No plan for heatwaves

In summer 2021, air temperatures in Canada broke records multiple days in a row as a powerful heatwave spread over the Pacific Northwest.

The town of Lytton, for example, set an all-time high-temperature record for Canada at 49.6°C (121.3°F). The heatwave’s effects were estimated to be 150 times more likely and about 2°C hotter due to human-induced climate change.

Key Numbers

49.6 ̊C

(121.3 ̊F) record temperature


heat-related deaths

The British Columbia Coroners Service registered over 500 heat-related deaths from 25 June to 1 July. Even after the hot spell ended, there was no immediate decrease in mortality, pointing toward the long-term health effects of heat stress. As with many disasters, the heatwaves disproportionately affected vulnerable populations, such as children, people with disabilities or chronic health conditions and those who were socially isolated or experiencing homelessness. Health risks also increased sharply with age, with the mortality rate doubling in every age group over 50 years old. Moreover, many of the deaths in individual residences occurred in lower-income neighbourhoods, where there is less of a cooling effect provided by surrounding greenery.

Overall, British Columbia was unprepared for heat as this level of heat was unprecedented in Canada. Unlike other hazards, no single organization or department in Canada is responsible for coordinating responses to extreme heat. The provincial government and many municipalities did not have heat action plans, cooling centres (such as libraries and recreation centres) had limited opening hours, and less than 35 per cent of private homes had access to air conditioning.

Heatwaves are among the deadliest natural hazards, and evidence shows that they will become more frequent and intense as the climate changes. Recognizing and responding to heat events as increasingly common public health emergencies are crucial to prevent further loss of life and well-being.

Heatwaves are among the deadliest natural hazards, and evidence shows that they will become more frequent and intense as the climate changes.

Wider picture

Global average temperatures have risen 1.1°C since 1880, and 9 of the last 10 years have been the warmest years on record. Extreme heatwaves will be three times more frequent in 2030 than in 2001, and the global average cumulative heat during heatwaves is increasing by as much as 4°C per decade in some regions. This changing climate creates new heat hazards in places that are unprepared and unaware of the dangers.

Inexperience is not an excuse however; citizens, organizations and governments can better prepare for worsening weather extremes and keep people safe from preventable disasters.

Root Causes

Gases released into the atmosphere by human activities contribute to increasing global warming and climate change

A lack of perception, awareness or preparation in governance relating to risk management and response


An absent or poorly communicated warning of a hazard’s impending arrival.

A prolonged shortage of water supply, often due to extended periods of insufficient rainfall.

Increasing temperatures in the ocean or atmosphere, for example from climate change.


Disasters cause fatalities both when they occur and in the aftermath with cascading effects on physical and mental health.

Public and private structures and systems can be impacted by disasters, from homes and properties to physical assets critical for providing health services, transport, food, water, communications and more.

Even those surviving disasters when they occur can be at risk of short- and long-term health impacts cascading from pollution or damage of critical infrastructure and livelihood disruption.

Just like people, nature also feels the impacts of various hazards resulting in threats to health and physical damage to individuals, populations, communities or entire ecosystems.

Reduction of people’s ability to support themselves or their family, both temporarily or permanently, is an impact that is interconnected with many others, including health and food security.


Green heat sinks: Urban greening, such as small parks, green roofs or home gardens, harnesses the power of nature to cool and refresh cities. In addition to acting as a heat sink, green urban areas also support biodiversity, sequestrate carbon, improve human health and create more enjoyable places.

Neighbourhood saftey net: Mutual care during heatwaves has been shown to be effective to reduce risk for the most vulnerable. Initiatives, such as Be-A-Buddy in New York, allow local volunteers to educate, prepare and assist other citizens who may be at risk. This not only improves support networks but also helps build community and social resilience.

Develop heatwave communication tools: Investing in ways to communicate risks and early warnings more effectively help to reduce heatwave impacts. Helpful tools include accurate extreme temperature prediction models, heatwave behaviour maps and warning systems linked to social media and mobile phones. In this way, residents can become more aware of risks while businesses can plan better to avoid losses.

Designate a heat response authority: There should be an authority responsible for managing heatwave mitigation and response among the various sectors (e.g. health, insurance, urban planning, energy, social services). Additionally, a heat alert and response system should be developed to warn the public through a method of organized communication to help people prepare and protect themselves.