Living with Extreme Heat

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.