How Climate Change Is Threatening Health in Canada — What to Know & What’s Being Done

Climate change is more than environmental — it’s a health crisis in Canada. Explore rising risks from heat, smoke, disease, how clinics are responding, and practical tips to protect yourself.

Introduction

Climate change isn’t some distant concern—it’s affecting health in Canada now. From record-breaking wildfires to blistering heat waves, the risks are growing. More people are being hospitalized or dying from extreme weather, poor air quality, and new disease patterns. Clinics and public health agencies are having to catch up: changing their protocols, offering new kinds of warnings, and helping individuals protect themselves.

In this article, I’ll walk you through:

• the main climate-related health risks facing Canadians (hot weather, smoke, vector diseases, etc.)
• who’s most vulnerable and how it differs by region
• how medical clinics and the health system are adapting
• what you can do personally to reduce risk
• what policies are in place, where gaps remain, and what the long-term outlook looks like

If you live in Canada—or are working in health or public policy—this is a guide for how climate change is affecting your health now, and how to manage it going forward.

Key Health Risks from Climate Change in Canada

Climate change increases several overlapping health risks. Below are some of the most serious ones, with up-to-date evidence and data.

Heat Waves and Extreme Heat

Heat is becoming more dangerous:

• In recent decades, about two‐thirds (66.3%) of Canada’s recorded heat-related deaths since 1981 have happened since 2016. That shows the trend is accelerating. The average annual heat‐related death rate is rising.
• The 2021 “heat dome” in British Columbia was a stark example: over 600 deaths linked to that one event, mostly in older adults living alone or with chronic disease, and almost all happening indoors.
• A study of 12 major Canadian cities between 2000-2020 found that during extreme heat events, non-accidental mortality rises substantially, particularly among those 65 years or older. Respiratory and cardiovascular deaths increase noticeably.

Health effects from extreme heat include heat stroke and exhaustion, dehydration, worsening of cardiovascular disease, kidney stress, risk for pregnant people, and even disproportionate death rates.

Air Quality & Wildfire Smoke

Wildfire smoke and poor air quality are already major health threats, and they’re getting worse.

• Canada’s wildfire season in 2025 is already among the worst on record. As of mid-September, over 8.7 million hectares have burned—well above what’s typical for this time of year.
• The 2023 wildfires caused huge spikes in PM₂.₅ (fine particulate matter) levels. Global exposure to smoke pollution from those fires was far above levels in 2017 or 2021.

Wildfire smoke harms more than your lungs. It can:

• worsen asthma, COPD, and other lung diseases
• trigger cardiovascular events (heart attacks, strokes)
• irritate eyes, nose, throat, and sinuses
• cause headaches, fatigue, even affect mental health over time

People can be impacted even when smoke isn’t obvious—air quality may be poor even if you don’t smell or see smoke. Vulnerable populations are especially at risk: young children, the elderly, people with pre-existing respiratory or cardiovascular conditions.

Table: Heat & Smoke Risks at a Glance

Vector-Borne & Infectious Diseases

Climate change is shifting disease patterns in Canada. Warming, changing precipitation, and longer warm seasons are enabling more vectors (like mosquitoes and ticks) to thrive, and increasing the risk of infectious diseases.

Mosquito- and Tick-Borne Diseases

• Diseases such as West Nile Virus and Lyme disease are appearing in broader regions. Health experts note that blacklegged ticks (which transmit Lyme) are now established in more parts of central and eastern Canada, moving northward as climates warm.
• A 2024 report from the Public Health Agency of Canada says Canada is seeing increased risk of arboviruses (viruses spread by mosquitoes) like West Nile, Eastern Equine Encephalitis, and others, due to conditions becoming more favorable for both mosquitoes and the pathogens they carry.
• Tick-borne parasites like Babesia microti and Babesia odocoilei, not historically common in some provinces, are being detected in places like British Columbia as habitats shift.

Waterborne, Foodborne & Other Infectious Hazards

• Warmer water temperatures and increasing frequency of heavy rainfall / flooding events are leading to greater risk of waterborne disease outbreaks. For example, lakes in Canada are warming faster than many global averages, increasing conditions for harmful bacteria or pathogens. Swimming advisories and beach closures are becoming more common in summer months.
• Storm runoff, combined with aging infrastructure, can overwhelm water treatment systems, allowing contaminants into drinking water or recreational waters.
• Food safety is also at risk. Warmer conditions can speed up spoilage and increase the chance of foodborne pathogens contaminating produce.

Efforts & Surveillance

• To respond, Canada has launched initiatives under the Infectious Disease and Climate Change Fund to build capacity, improve awareness, and strengthen monitoring of climate-sensitive infectious and zoonotic diseases.
• In Ontario, new guidelines for climate-change health impacts emphasize tracking vector-borne illness, food and waterborne disease, and air pollution, to guide public health action.

Water & Food Safety, Food Security

Changing climate affects not just pathogens but the systems that deliver clean water and safe food. These are foundational to keeping people healthy.

• Floods and heavy rainfall can lead to water contamination: runoff carries nutrients, soil, industrial pollutants into rivers, lakes and reservoirs. After floods, risks of Giardia, Cryptosporidium, and bacterial contamination rise.
• Droughts reduce water levels, concentrate pollutants, and can lead to poor water quality (higher temperatures, lower oxygen).
• Impact on food supply: crop yields may suffer in some regions due to heat stress, drought or pests, leading to higher prices or food shortages. Cold-hardy crops may shift north; traditional crops in some areas may no longer be viable.
• Nutrition and access: Indigenous, remote, and poorer communities often face higher food costs and reduced access to fresh produce. When climate shapes crop availability and supply chains, these disparities are magnified.

Mental Health Impacts

Health risks from climate change aren’t only physical. Psychological stress, trauma, and mental health disorders are becoming more common as communities deal with disasters, environmental degradation, and uncertainty.

• After extreme weather—wildfires, floods, heat waves—many people report anxiety, depression, grief, even PTSD. The loss of homes, displacement, and witnessing damage erode sense of safety.
• Long periods of poor air quality (smoke) or heat can increase irritability, disruption of sleep, reduced ability to concentrate, especially for people with preexisting mental health conditions.
• Vulnerable groups are disproportionately affected: Indigenous peoples, people in remote communities, those with low socio-economic status, or limited access to mental health care.
• Policy documents are now recognizing mental health explicitly as part of climate health risk assessments. For example, new adaptation planning often includes “behavioral and community mental health” responses post-disaster.

Regional Differences Across Canada

Canada is large, with varied climates, geography, and population density. These differences matter a lot when it comes to climate change health risks and how well systems can respond.

Variation by Province, Territory, Urban vs Rural

• Urban heat islands where pavement and buildings trap heat tend to make cities much hotter than surrounding rural areas at night. In cities such as Toronto, Montréal, Vancouver, and Calgary, this magnifies heat-wave risks. (Health Canada report on urban heat islands)
• Rural and remote areas often have less infrastructure (cooling, healthcare access), longer distance to clinics or hospitals, and sometimes less investment in warning systems.
• Northern and Indigenous communities are already experiencing significant temperature shifts, less predictable weather, and more limited local services. Climate variability in these areas can disrupt traditional food sources, increase exposure, and magnify risk. (EHP on Climate Change and Health Vulnerability)

Who’s Most At Risk in Different Regions

Case Examples

• In British Columbia, the Kootenay-Boundary health region has conducted a climate change and health vulnerability/adaptation assessment; their heat warning system is region-specific, triggering alerts when thresholds are crossed in the local climate. (Interior Health V&A report)
• Toronto and Montréal have both reported that their heat alert systems increase awareness among residents, encourage protective behaviours (drinking water, staying in cool places), and reduce some hospital admissions during heat events. (Adaptation and Health System Resilience report)

How Clinics and the Health System are Responding

Medical clinics, public health units, and hospitals are adapting in several ways. Some changes are reactive (during heat waves or wildfire events), others are proactive.

Heat Alert & Response Systems (HARS)

• Many provinces and health authorities now maintain HARS plans—these are structured systems that trigger warnings, coordinate communication, set up cooling options, and monitor vulnerable populations. A recent stocktake showed that while HARS is widespread across Canada, its features vary: some systems only issue alerts, others involve community outreach, evaluation, and long term preventive measures.
• Challenges: funding, unclear responsibilities between agencies, identifying who is most at risk (mapping). Some regions suffer from “alert fatigue” where people ignore frequent warnings.

Clinic & Hospital Infrastructure

• Clinics are adjusting by improving cooling and ventilation. Some larger hospitals now have upgraded HVAC systems, and plans exist in several jurisdictions to ensure that during extreme heat, facilities can maintain safe indoor temperatures.
• Air filtration or purification in clinics is being considered more, especially in areas frequently affected by wildfire smoke. Clean air shelters / cooling centres are also becoming part of system planning.

Protocols, Training & Outreach

• Health practitioners are being trained more consistently to recognize heat illnesses, smoke exposure effects, and vector-borne disease symptoms. Some clinics distribute guidance materials to patients ahead of heat or smoke seasons.
• Public health units conduct outreach in advance of wildfire seasons (e.g. awareness about indoor air quality, how to minimize exposure). There’s also more coordination with weather services and environmental agencies to issue warnings.

Equity and Access Issues

• Vulnerable populations (older adults, those with chronic disease, low income, Indigenous communities) often have less access to cooling, clean air, or transport to shelters. Clinics in remote locations may lack resources to upgrade infrastructure.
• Language, digital access, and communication formats can be barriers—outreach in multiple languages, printed materials, in-person community liaison are being used in some areas to reach those who are disconnected from online alerts.

What Individuals Can Do to Protect Health

Even though many health risks from climate change are systemic, there are many practical steps you can take personally to reduce exposure, protect yourself, and help your community. These apply whether you live in a city, rural area, or remote location.

Tips for Heat, Wildfire Smoke, and Poor Air Quality

• Monitor warnings and air quality: Pay attention to local heat alerts, wildfire smoke advisories, and the Air Quality Health Index (AQHI). These give early signals so you can act.
• Limit exposure during high-risk times: Avoid strenuous outdoor activity during peak heat hours or when smoke is heavy. Late afternoon into early evening are often worst.
• Stay cool indoors: Use air conditioning if available. If not, use fans, keep blinds or curtains closed during daytime, open windows when the outdoor air is cooler (but only if smoke isn’t heavy). Block sun with shades or reflective window coverings.
• Clean the air: Use high‐efficiency filters (e.g. HEPA) in HVAC systems or portable air cleaners. Avoid indoor pollution sources during smoke events: no wood stoves, limit cooking using ovens or stoves that generate heat or fumes.
• Hydrate and adapt your clothing: Drink water even before feeling thirsty. Wear light, breathable clothing. Use wet towels or cool showers to reduce body temperature.
• Have a plan for vulnerable people in your care: Check on elderly neighbours, children, people with chronic illness. Make sure they have safe, cool spaces to rest and escape smoke.

Health Canada guidance “Wildfire Smoke with Extreme Heat” combines many of these steps into a framework for dealing with overlapping conditions. It emphasizes that cooling is often more urgent than avoiding smoke when heat is life-threatening.

Recognizing Medical Emergencies

• Heat-related emergencies include symptoms like confusion, high body temperature, vomiting or seizures. If someone shows these, get medical help immediately.
• Smoke exposure can cause severe breathing problems, chest pain, persistent cough, or worsening of heart or lung disease. Seek medical attention if symptoms worsen.

Preparing Your Environment

• Identify a cool room in your home or where you live. Make it as comfortable as possible: shade, fans, sealed windows when smoke is heavy.
• Know where community cooling centres are located (libraries, community centres, malls). Many provinces list these publicly.
• Ensure your home has working thermometers indoors. In BC, for example, indoor temperatures over 31 °C are considered dangerous for vulnerable people.
• Keep supplies ready: water, light clothing, masks (N95 or equivalent when needed), first-aid kit, maybe an air purifier or spare filters.

Policy, Public Health Strategies, and Gaps

Strong individual action helps, but systemic changes make the biggest difference. Here’s what Canada’s governments and public health bodies are doing, and where more work is needed.

Current Federal & Provincial Measures

• Canada has been strengthening Heat Alert & Response Systems (HARS) across many provinces. These coordinate warnings, public outreach, and community resources during heat events.
• Some provinces, such as British Columbia, offer detailed guidance on preparing homes for heat, including tips on airflow, reflective coverings, and how to identify cooling centres locally.
• Public health agencies are incorporating overlapping hazard guidance—events that combine heat + wildfire smoke are specifically addressed in national documents. Measures include prioritizing cooling over opening windows when smoke is heavy, recommending masks, and giving special advice to vulnerable populations.

Gaps and Challenges

• Uneven coverage: Not all regions have equally mature alert systems or cooling infrastructure. Remote, Indigenous, and rural communities often lag behind.
• Role clarity and funding: The NCCEH check-up found that many HARS plans exist only in outline or internal documents; there are challenges in staffing, consistent funding, and assigning responsibilities.
• Overlapping hazards: When heat and wildfire smoke happen together, or during power outages, existing plans may not cover combined risks well. Guidance may conflict (e.g. whether to close windows to keep smoke out vs open windows for cooling).
• Accessibility and equity: Communication barriers (language, digital divides), lack of access to air conditioning or clean air, housing that makes cooling difficult, and social isolation are persistent problems.
• Evaluation & ongoing improvement: Many response systems lack robust evaluation of what works, which interventions reduce hospitalizations or deaths most. Feedback loops are needed.

Long-Term Outlook and Projections

Looking ahead, health risks from climate change in Canada are expected to increase—often sharply—unless major mitigation and adaptation happen. These projections cover mortality, disease burden, economic impact, and what the future may look like regionally.

What Canadian Projections Show

• Heat-related illness and deaths are projected to double or even quadruple in some provinces by 2050 if warming continues under current trends. For example, Québec studies show rising summer temperatures are linked with thousands more emergency room visits and hospitalizations as early as mid-century.
• Canada is warming at about twice the global average, which means the magnitude of health risk escalations (heat, wildfires, vector expansion) is likely more severe than many other countries will see.
• Economic studies (e.g. through the Canadian Climate Institute) project that health costs, workforce productivity losses, and infrastructure damages due to extreme heat may result in losses amounting to billions of dollars per year by mid-century.

Scenarios to Watch

Here are two broad possible futures:

What Needs to Change

To avoid the worst outcomes:

• Canada must meet its emissions reduction targets (e.g. the goal of net zero by 2050).
• Health systems must be climate-resilient: clinics & hospitals should be prepared for overlapping hazards (heat + smoke + power outages, for example).
• Equity must be front and centre: remote, Indigenous, low-income communities need targeted resources.
• Monitoring, research, and evaluation need scaling: knowing what interventions work, where, and for whom helps avoid wasted effort or unequal outcomes.

Conclusion

Climate change health risks in Canada are not hypothetical—they’re already impacting many of us through heat waves, wildfire smoke, shifting disease patterns, and pressure on healthcare systems. Clinics, public health agencies, and governments are adapting, but there are serious gaps, especially for vulnerable populations and in remote regions.

What you can do now:

• Pay attention to alerts for heat, air quality, and wildfire smoke
• Make your home and routines safer during high-risk conditions
• Support and advocate for strong local adaptation and mitigation policies

By acting both individually and collectively, we can reduce many of the worst health impacts—and help build a healthier, more resilient Canada.

FAQ