What are extreme heat events?
Extreme heat events, often referred to as "heat waves," are prolonged periods of excessively high temperatures outdoors. Dr. Sarah Henderson, the scientific director of environmental health services at the BC Centre for Disease Control, indicates that such events are increasingly frequent due to climate change. A rise of 1.5 degrees Celsius represents the global average over time, but some regions are already facing even higher temperatures and more severe extreme heat episodes. For instance, during the 2021 heat dome in British Columbia, temperatures soared 15 to 25 degrees Celsius above normal for several days.
The impacts of extreme heat
Extreme heat affects both human health and the environment. Dr. Henderson explains that our bodies strive to maintain a core temperature around 36.6 degrees Celsius (97.88 degrees Fahrenheit). However, it becomes extraordinarily difficult to stay cool in hot conditions, especially for elderly individuals or those with pre-existing health issues. While a room at 26 degrees Celsius (80 degrees Fahrenheit) may feel warm, temperatures of 31 degrees Celsius (88 degrees Fahrenheit) and above can pose serious risks for vulnerable individuals. “If your core body temperature rises to 39 to 40 degrees Celsius (102 to 104 degrees Fahrenheit), you could be facing a life-threatening situation and need to cool down and seek medical assistance immediately,” warns Henderson.
The environmental consequences of extreme heat are extensive and intricate. According to Henderson, extreme heat is part of a broader chain of interconnected climatic changes. She cites the 2021 heat dome as a case in point, where the province was already experiencing drought before the extreme temperatures struck in late June. The resulting heat caused marine life casualties along coastlines, impacted poultry deaths, and disrupted food and water supplies. This led to lightning storms, which ignited wildfires and produced smoke. When rainfall finally occurred, it caused severe flooding and landslides, which adversely affected agriculture by flooding crops and livestock.
Get ready for the heat
To mitigate the risks associated with extreme heat, evaluating and prepping our living spaces is crucial. “Most heat-related deaths occur because it becomes too hot indoors; homes and buildings can overheat,” notes Henderson. Often during extreme heat events, nighttime relief might not adequately cool homes before the following day’s temperature rise. If your residence remains too hot during heat waves, it’s vital to seek cooler environments. Familiarize yourself with your city’s extreme heat protocol and identify local cooling centers. Typical places include libraries and community centers, with additional air-conditioned options like cinemas and shopping malls. Community pools and spray parks may also extend their hours during these times.
Strategies to help weather the heat
Here are some suggestions to help you and your family cope with extreme heat at home:
- Create a heat action plan with your family and stay informed about local heat alerts.
- If you have air conditioning, keep it running. If not, consider portable or window air conditioners for targeted cooling in one or two rooms.
- Utilize suitable window coverings and fans, understanding that these alone may be insufficient during extreme heat.
- Block heat from entering your home, perhaps by using cardboard on the exterior of windows; this can lower indoor temperatures by 2 to 3 degrees Celsius.
- Monitor indoor temperatures; Henderson suggests using an inexpensive digital thermometer.
Innovative urban design solutions
The "urban heat island effect" describes how urban areas capture and emit heat, making them significantly warmer than rural surroundings. This phenomenon is exacerbated by a lack of trees, the prevalence of hot concrete and asphalt surfaces, and tall structures that obstruct cooling breezes. Given that the majority of us reside in cities, urban design plays a vital role during extreme heat events. Effective building design, urban planning, and the integration of more greenery can create positive impacts. Henderson points out that strategic planning should also ensure our energy infrastructure remains reliable during extreme heat situations.
Henderson emphasizes that social connections are essential for coping with the climate crisis and enhancing resilience. “Engaging with our communities means we have a larger network of people who care about each other. We can support one another,” she asserts. She encourages everyone to take initiative—perhaps through volunteering at local organizations—to strengthen important social bonds within the community, which also contributes to improving our surroundings.
Extreme heat—by the numbers
- 619 deaths in BC were attributed to the 2021 heat dome.
- 49.6 degrees Celsius (Canada’s highest recorded temperature) was documented in Lytton, BC, during the 2021 heat dome, just days before 90 percent of the town was destroyed by fire.
- Surface temperatures in intertidal zones reached 50 degrees Celsius (and higher!) during the heat dome, exceeding survivability limits for marine organisms like oysters and crabs.
- The summit of an Italian glacier recorded a record-high temperature of 10 degrees Celsius in 2022, the day before it collapsed.
- Australia experienced unprecedented temperatures and wildfires in 2020, resulting in the burning of more than 11 million hectares.
Who is most at risk
Various factors influence vulnerability to extreme heat events, including individual health and housing circumstances. “The effects of climate change are not equitable; they are distributed unequally,” underscores Dr. Sarah Henderson. “We must approach this issue with compassion.” Those most at risk without access to air conditioning include:
- Older individuals living alone
- People with mental health issues
- Individuals with disabilities or chronic health conditions
- Those with substance use disorders
- Workers in high-temperature environments
- Marginally housed individuals
- Pregnant women, infants, and young children
Where there’s smoke …
Extreme heat events heighten the danger of wildfires, increasing health risks for both humans and wildlife. Wildfire smoke can irritate lungs, trigger inflammation, and potentially disrupt the immune system. When air quality is poor due to smoke, it’s advisable to keep windows closed if safe. However, Dr. Sarah Henderson suggests that during extreme heat conditions, it is generally better for most individuals to open windows at night to welcome cooler air, as overheating poses a more significant health threat than smoke inhalation. Using air purifiers equipped with HEPA filters can also be beneficial.
It takes a village
Be sure to regularly check in on family, friends, and neighbors during extreme heat events.
Don’t forget to hydrate!
It’s vital to drink plenty of fluids in hot weather—avoid sugary beverages and alcohol, as they may lead to dehydration.
Tips and tricks to stay cool
- Sleep in the coolest area of your home, or even consider sleeping outside if possible.
- Try wearing a damp shirt at night or cooling your sheets.
- Take cool baths or showers.
- Keep windows and coverings shut during the day and open them at night.
Extreme heat/climate resources
For additional information, please refer to the following helpful resources.
