FAQ: Wildfire Smoke and Extreme Heat

Our classrooms are not air conditioned and we are experiencing both heat and wildfire smoke. What should we do to reduce the health risks? 

Both wildfire smoke and extreme heat can harm your health. Health risk is amplified when extreme heat occurs at the same time as a wildfire smoke event. Children are more susceptible to the health impacts of both of these climate-related health risks.
- Wildfire smoke poses greater health risks to children because their bodies, brains and lungs are still developing, and they breathe more for their size compared to adults
- Children are at increased risk of heat-related illness because their bodies have limited ability to adjust to heat, they can get dehydrated more easily,  and their sweating rates are lower than adults 
- Young children may not be able to notice or communicate when they are feeling unwell. 
- Exposure to extreme heat and to wildfire smoke have been associated with mental health conditions including depression and anxiety in children.

Without air conditioning, indoor temperatures can get dangerously hot during extreme heat events. Health Canada recommends prioritizing keeping cool when an extreme heat event occurs at the same time as a wildfire smoke event. Strive to keep indoor temperatures below 26°C.

Make a plan. Before the wildfire and heat season starts, have a climate-readiness plan in place outlining how you/your staff will prepare and respond to wildfire smoke and heat events. Assess your setting’s capacity to maintain safe indoor temperatures and clean indoor air, and check with your local authorities to identify public spaces, such as community centres with air conditioning and air filtration, that you can access if needed. Learn more about measures that schools and child care programs can take to reduce the health risks of wildfire smoke here: FAQ: Wildfire Smoke

Take action. During a wildfire smoke and heat event, keep smoke and heat out and filter the indoor air.
- Keep windows and doors closed (if it is safe to do so without overheating) to keep the indoor environment both cool and protected from wildfire smoke. 
- Block the sun by closing curtains and blinds and using awnings during the day to keep indoor spaces cooler.
- Limit the use of exhaust fans such as bathroom fans as they can draw smoke indoors through cracks and other small openings in the building’s exterior. 
- Reduce sources of indoor heat by avoiding the use of the oven, dryer, dishwasher and other devices that generate heat until after hours. 
- Reduce or avoid the use of appliances and activities that can increase fine particulate matter (PM_2.5) levels indoors (e.g., gas stoves, vacuuming). 
- Use clean, good quality air filters in your ventilation system or portable air cleaners (commercial or DIY) with the highest particle removal rating based on manufacturer’s specifications. Check filters regularly and clean/change when needed.

Consider ways to monitor temperature, humidity and  indoor air quality, to ensure that safe conditions are maintained during combined extreme heat and wildfire smoke events. Monitor/measure indoor temperatures in rooms where children spend time (risk increases at indoor temperatures greater than 26°C, and above 31°C can be dangerous, especially for susceptible groups). Consider a device to measure relative humidity levels (between 35% and 50% is recommended). Consider using air sensors that measure PM_2.5 (the primary pollutant of concern in smoke) to compare  indoor and outdoor levels so you can  monitor how well the filtration system is working.

Know when to vacate the space. If indoor temperatures are approaching dangerous levels and wildfire smoke is too heavy to open windows for cooling, the safest option is to discontinue the use of the space and seek out cooler and cleaner air spaces.