More than 200 wildfires are raging across Canada, sending a thick blanket of choking smoke through the U.S. Midwest. Experts says climate change means U.S. residents better get used to it.

The U.S. Environmental Protection Agency warns that wildfire smoke contains dangerous pollutants in the form of fine particles known as PM 2.5 that can penetrate deep into the lungs and enter the bloodstream. Short-term exposure can lead to bronchitis, worsen asthma and create other health issues.

Wildfires scorching several Canadian provinces have driven at least 33,400 people from their homes, with smoke now reaching all the way to Europe.

According to the Ontario’s Air Quality Health Index (AQHI), areas that had “high risk” ratings on Friday were Belleville, Brampton, Brantford, Burlington, Cornwall, Grand Bend, Guelph, Hamilton, Kingston,

Wildfire smoke drifting in from the Prairies and northwestern Ontario is expected to cause reduced visibility and poor air quality, Environment Canada says.

A strong front may trigger severe thunderstorms through parts of Ontario on Wednesday, but wildfire smoke and the timing of the system could limit the development

The official start of summer is still weeks away — but experts are already warning residents to brace for a hot, stormy season with the looming threat of wildfire smoke.