“Unprecedented” wildfires in eastern Canada have prompted authorities in Toronto and Ottawa, as well as New York in the United States, to warn residents of the health risks of polluted air.

This year’s wildfire “season” has started quite early, with experts fearing it will be the worst summer in the country’s history for extreme heat, drought and wildfires. Weather conditions are expected to stay that way for months.

According Reuters, there are fires in almost all 10 provinces and territories of Canada, with Quebec to the east being the hardest hit. A little further west, the capital Ottawa scored the worst air quality on Canada’s Environmental Health and Air Quality Index, indicating a “very high risk” to people – all because of the forest fires in Quebec.

Smoke from wildfires can harm health even in low concentrationsand people with lung or heart disease, as well as the elderly, children and pregnant women are at higher risk, according to Environment Canada.

Effects in the United States

Wildfires are common in Canada’s western provinces, but this year they erupted early and with surprising force in the east of the country, forcing the Canadian government to evacuate homes and deploy troops. The United States, Mexico, South Africa and France sent firefighters to help bring the blaze under control.

With this, the United States was also affected. The New York State Department of Environmental Conservation has issued a health alert for counties including New York, the Bronx and Queens.

The state has even recommended that residents consider limiting outdoor physical activity to reduce the risk of adverse health effects.