“Extreme heat is costly and deadly—and it’s getting more frequent and intense throughout Canada.” – Canadian Climate Institute
People living in Canada are feeling the effects of climate change through more extreme weather events such as extreme heat, heatwaves, and an increasing number of hot days. Recent heatwaves across western Canada have many people asking: will our healthcare systems be able to cope with a warmer and less predictable climate? And can our communities adapt to warmer temperatures to safeguard their health and well-being?
There are five factors that influence the health effects of a heatwave (Health Canada 2011):
Extreme heat can worsen existing health conditions, including cardiovascular conditions, respiratory illnesses, and mental health issues. Direct health impacts can include dehydration and heat exhaustion, which can quickly progress to more life-threatening situations, such as heat stroke, and even death. These risks are exacerbated for specific populations such as older adults, infants and young children, and individuals with pre-existing physical and mental health conditions. The impact on population health can also be profound, as prolonged exposure to extreme heat can cause strain on healthcare systems. Increased emergency room visits and hospital admissions for heat-related illnesses contribute to this strain, particularly in areas with limited resources or inadequate infrastructure. Due to these adverse health impacts, and the anticipated escalation of temperatures in coming years, more adaptation actions are needed to better protect people in Canada from extreme heat.
Box 1: Extreme heat in Canada – B.C. Heat Dome of 2021
In late June 2021, a heat dome event settled over British Columbia resulting in record high temperatures across the province over a week-long period. At the peak of the extreme heat event, daytime temperatures were above 40 °C in some parts of the province. Overnight temperatures were also well above typical for most areas, exacerbating the impacts of the extreme heat by reducing the opportunity for the body to cool down overnight. The heat dome resulted in 619 confirmed deaths. As a result of this event, the Chief Coroner of B.C. convened a review panel to investigate the specific circumstances around these deaths and to identify potential actions to reduce future health risks. Three of the key actions identified were:
This event showed that to best prepare for what the future may hold, understanding how temperatures, particularly temperature extremes, are expected to change in the future is critical.
Due to climate change, extreme heat events are becoming more frequent and intense across Canada, posing significant challenges to public health and well-being. In response, Canadian provinces, territories, and local health authorities/units are working to adapt to and mitigate the impacts of rising temperatures through comprehensive planning, infrastructure investments, and community engagement. These efforts will be essential for not only protecting people in Canada from the health impacts of extreme heat but also creating safer, more resilient, and sustainable communities for generations to come.
Since 2008, Health Canada’s Extreme Heat Program has been aimed at addressing the health risks associated with extreme heat. Through the development of research, guidance, and tools, Health Canada has collaborated with partners across the country to enhance heat preparedness and response. A notable achievement is the widespread adoption of Heat Alert and Response Systems (HARS), which have expanded considerably. In 2008, HARS only covered a limited number of health authorities. However, by 2023, they covered 79% of all Canadian health authorities.
Box 2. What are Heat Alert and Response Systems?
Heat Alert and Response Systems (HARS) are comprehensive plans and strategies to address the health risks associated with extreme heat events. These systems are generally made up of five parts:
Source: HARS Best Practices Guidebook
Along with the emergency response actions contained as part of a comprehensive HARS, more preventative actions can be implemented to protect at-risk populations from the health impacts of extreme heat. These preventative actions include assessing heat-health vulnerability, reducing urban heat islands, and addressing the mobility and transportation needs of at-risk populations to locations that are safe from the heat (e.g. designated cooling shelters). These examples of preventative heat-related actions are informed by the best available scientific evidence. Collaboration between policymakers, public health officials, community organizations, and other partners is also essential for developing and deploying solutions that address the specific needs and vulnerabilities of diverse populations.
In 2022, Health Canada published a comprehensive scientific assessment–titled “Health of Canadians in a Changing Climate: Advancing our Knowledge for Action” – that evaluated the latest research and knowledge to inform people in Canada about the effects of climate change on health and health systems, populations most at risk of these effects, and adaptation measures taken in Canada. This assessment informed the health and well-being section of Canada’s National Adaptation Strategy (NAS), a pan-Canadian strategy released in June 2023 that outlines a whole-of-society approach to building climate-resilient communities. The NAS is organized around five interrelated systems – including health and well-being – each of which have goals and objectives to guide adaptation action.
One key objective under the health and well-being system is that “health systems have the expertise, knowledge, and resources needed to identify climate change-related risks and take equitable, evidence-based action to protect health.” To achieve the objectives under this system of the NAS, relevant and usable climate data must be accessible to professionals in the health sector to help them implement these evidence-based adaptation measures that protect Canadians from extreme heat.
Box 3: Heat waves in Québec
Over the last 15 years, Québec has experienced substantial health impacts from extreme heat waves. For example, in July 2010 health officials documented 280 excess deaths from heat-related causes. In July 2018, when temperatures in Montréal spiked as high as 35.3°C, 86 probable deaths were reported, along with major increases in emergency admissions to hospitals.
In response, the Québec Government as well as local and regional health authorities and communities, have implemented monitoring, planning, and emergency response measures to prevent heat-related health risks and enhance preparedness. These heat-related actions are documented in the following case study. Québec’s work to protect residents from extreme heat underscores the importance of proactive measures to address the health consequences of extreme heat events in the region and serves as one example of how Canadian provinces and territories can work to adapt to extreme heat.
Understanding how the climate is expected to change is critical for making decisions for reducing future impacts. For extreme heat impacts, understanding future temperature trends can aid decision-makers in developing locally relevant adaptation actions that will reduce the risks of extreme heat on public health. ClimateData.ca’s Health Sector Module contains various data products, case studies, links, and tools that can help decision-makers as they look to reduce heat-related health risks.
ClimateData.ca’s Analyze Tool allows decision makers to calculate a wide range of climate indices using custom climate threshold values, such as the number of days per year where the maximum temperature exceeds 40°C. This is an example of a context-specific limit beyond which potential impacts, including increased illness, disease, emergency room visits, mortality, or damage to critical health infrastructure may result.
The Spatial Analogues app is one of ClimateData.ca’s newest and most powerful tools. It provides a novel way of visualizing future climate changes by allowing users to envision and prepare for their city’s future climate by exploring cities that are already experiencing similar climatic conditions. Looking to Québec City as an example, as the climate warms, the city is expected to experience considerable climatic changes—from more frequent and intense heat to shifting precipitation patterns.
Designing Future-Ready Buildings
Typically, the design of buildings, including key health-related infrastructure such as hospitals, relies on climate data from historical records. However, we now know that the past is no longer a good indication of the future when it comes to climate. To increase the resiliency of our health systems, designing health-related infrastructure using future climate data may be the best approach. ClimateData.ca has a Learning Zone Module dedicated to sharing different kinds of future climate data specifically tailored to the planning and design of Canadian buildings. The Module includes:
As Canada addresses escalating challenges from rising temperatures and extreme heat events, it is important to prioritize actions that safeguard public health. Recent events, such as the heat dome in western Canada in 2021, underscore the urgency of implementing effective adaptation strategies to protect at-risk populations. Ongoing efforts to enhance Health Canada’s extreme heat programming can help bridge these gaps and improve community resilience. At the same time, data tools on ClimateData.ca offer strategies for analyzing climate data and designing infrastructure to withstand rising temperatures.
Visit Health Canada’s website for more information.
For further information on the overlaps between health and climate change, read additional articles in this series, and explore the reference list below.
References
This project was undertaken with the support of:
