Public Information

Emergency Management

Important Health Notices for Health Care Professionals

Forest Fire Smoke and Your Health

What's in forest fire smoke?

Forest fire smoke is made up of a mixture of gases and very small particles that are produced when wood and other organic matter burn. The small particles in forest fire smoke also occur with many other types of air pollution and have been linked to serious effects on people’s health. Smoke also contains toxic gases like carbon monoxide, that can also be harmful to your health.

Smoke particles are small and so can get deep into your lungs. Some particles are even small enough to get into the alveoli, or air sacs, of your lungs and may be absorbed into the bloodstream.

What are short-term health risks?

Your body will try to protect itself against the smoke particles by making more tears and mucous. This can cause runny noses, scratchy throat, irritated sinuses and headaches. If the smoke is heavy and lasts for days or weeks, you may also develop a cough.

People who already have heart or lung problems may feel the effects of smoke earlier and worse than others in the community.

Who is most at risk?


How can I protect myself and minimize the health effects of fire smoke?


If you experience difficulty breathing or other symptoms that you cannot control by getting out of the smoke, consult your healthcare provider or call Telehealth Ontario (1-866-797-0000 or TTY at 1-877-797-0007).

When are smoke levels dangerous?


Where can I learn more about local conditions?

Local conditions can change quickly. Please refer to the Ontario Ministry of Natural Resources :


Thank you to the Thunder Bay District Health Unit and the NorthWestern Health Unit for contributing to this document.

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