alive logo

Living with Extreme Heat

How we’re impacted and what we can do


If you’ve found yourself wondering if summers are hotter (and smokier!) than they were when you were little, you’re not alone. You’re not imagining it: extreme heat events are increasing due to climate change. This heat has major impacts on our health and on our environment. Thankfully, there are many steps we can take to help protect ourselves, our families, and our communities.


What are extreme heat events?

Sometimes known as “heat waves,” extreme heat events refer to stretches of time with very high outdoor temperatures.

Dr. Sarah Henderson is the scientific director of environmental health services at the BC Centre for Disease Control. She explains that extreme heat events are becoming more common as our climate is changing.

A change of 1.5 degrees Celsius refers to the global average over time, and some parts of the planet are already experiencing bigger increases and more intense extreme heat events. In the 2021 BC heat dome, we saw temperatures that were 15 to 25 C higher than seasonally normal, and they lasted for days.


The impacts of extreme heat

Extreme heat has effects on our bodies as well as on our environment. Henderson explains that our bodies always try to maintain a core temperature of approximately 36.6 C (97.88 F). But in a hot room, it’s a very challenging task for our bodies to keep cool, especially for those who are older or who have chronic health conditions.

A 26 C (80 F) room may feel uncomfortably warm, but beyond that temperature, the risk increases. A temperature of 31 C (88 F) or higher can be dangerous for susceptible people. “If your core body temperature reaches 39 to 40 C (102 to 104 F), you are in a life-threatening situation, and you must seek medical attention and start to cool down immediately,” Henderson warns.

When it comes to the environment, impacts are far-reaching and complex. Henderson explains that extreme heat is part of a chain of events that can never be disconnected. “Climatic changes do not happen in a vacuum,” she says.

Henderson uses the 2021 heat dome as an example. The province was already in a period of drought when the extreme heat hit in late June. As the temperatures rose, marine life died on shorelines, poultry died, and our food and water supplies were affected.

Then came lightning storms, which led to wildfires and smoke. When rains finally hit, the province then experienced extreme flooding and subsequent landslides. Agriculture was impacted once again, as crops and livestock were flooded.


Get ready for the heat

One of the most important steps we can take to protect ourselves and deal with the heat is to assess and prepare our homes. “Most people die in the heat because it’s too hot inside; homes and buildings overheat,” Henderson says. At night during extreme heat events, our homes may not cool down to a safe temperature before rising again the following day.

During high heat, if your home isn’t cool enough, it’s important to leave to seek cooler temperatures. Research your city’s extreme heat plan and learn about local cooling centres. Common locations include libraries and community centres. Other areas with air conditioning include movie theatres and malls. Community pools and spray parks may also have extended hours.


Strategies to help weather the heat

The following tips can help you and your family weather the heat in your own home.

  • Develop a heat action plan with your family and pay attention to local heat alerts.
  • Install air conditioning, but if central air conditioning is not an option in your home, consider portable or window air conditioners to keep one or two rooms cool.
  • Use appropriate window coverings and fans. These strategies used on their own without air conditioning, though, may not be sufficient in extreme heat events.
  • Block heat from coming inside (such as with cardboard on the outside of windows); this may reduce the temperature inside by 2 to 3 C.
  • Ensure you can track the temperature inside; Henderson recommends a low-cost digital thermometer.


Innovative urban design solutions

The term “urban heat island effect” explains how cities trap and radiate heat. In comparison, the countryside is much cooler. In urban areas, the lack of trees, the hot concrete and asphalt surfaces, and the tall buildings that block cool breezes are all factors.

Most of us live in cities, so the way these areas are constructed has a big impact during extreme heat events. Smart building design, urban planning, and adding more trees and green space can make a positive difference.

According to Henderson, smart planning can also mean making sure that our energy supply is robust and won’t fail during an extreme heat event.


Resiliency through community connection

Henderson stresses that social connection is our greatest hope—and our greatest tool—for navigating the climate crisis and building resiliency. “Integrating ourselves into our communities means that there is a larger group of people who we care about and who care about us. We can support each other,” she says.

Henderson encourages us each to do one thing—perhaps volunteering at a local nonprofit—to foster important social ties within our community. The bonus? We help improve the world around us.

Extreme heat—by the numbers

  • 619 deaths in BC were attributed to the 2021 heat dome
  • 49.6 C (Canada’s hottest ever recorded temperature) was recorded in Lytton, BC, during the 2021 heat dome—days before 90 percent of the town burned to the ground
  • 50 C (and higher!) were the surface temperatures in intertidal zones during the heat dome, which is well above the survival threshold for marine life such as oysters and crabs
  • 10 C was the record-high temperature at the summit of an Italian glacier in 2022, a day before it collapsed
  • 2020 saw record-breaking temperatures and wildfires in Australia, which burned more than 11 million hectares

Who is most at risk

Many risk factors for extreme heat events are at play, such as our health and our housing situation. “The impacts of climate change are not uniformly distributed. They are very inequitable,” says Dr. Sarah Henderson. “We need to be compassionate and considerate.”

Those most at risk if they do not have access to air conditioning include

  • older people who live alone
  • people with mental illnesses
  • people with disabilities and chronic health conditions
  • those with substance use disorders
  • those who work in hot environments
  • those who are marginally housed
  • pregnant women, infants, and young children

Where there’s smoke …

Extreme heat events increase the risk of wildfires, furthering the health risks to people and wildlife. Wildfire smoke pollution irritates our lungs, causes inflammation, and can even affect our immune function.

When the air outside is smoky, close your windows if safe to do so. However, Dr. Sarah Henderson maintains that in extreme heat events, it is still better for most people to open their windows at night to let in cool air because overheating is a bigger health risk than breathing smoke. Air purifiers with HEPA filters also help.

It takes a village

Check in on your family members, friends, and neighbours often during extreme heat events.

Don’t forget to hydrate!

Drinking enough is crucial in hot weather—but avoid sugary drinks and alcohol, which can cause dehydration.

Tips and tricks to stay cool

  • Sleep in the coolest part of your house, or even outside if you can.
  • Wear a wet shirt to bed, or cool your sheets.
  • Have a cool bath or shower.
  • Close your windows and coverings during the day and open them at night.

Extreme heat/climate resources

For more information, check out the following helpful sources.

Extreme Heat Preparedness Guide by Prepared BC

Wildfire Preparedness Guide by Prepared BC

“Health Checks during Extreme Heat Events” by the National Collaborating Centre for Environmental Health

“Wildfire Smoke” by BC Centre for Disease Control

“Extreme Heat Events” by Health Canada



No Proof

No Proof

Raise a glass and say cheers to not-so-hard drinks

Matthew Kadey, MSc, RDMatthew Kadey, MSc, RD