The smoke is expected to remain over the northern and central Plains of the United States for the next couple of days, according to meteorologists.

Out with the heat, in with the smoke.Just as Toronto's fifth heat warning this year was lifted, Environment Canada issued a special air quality statement for the city Wednesday night.The statement is the result of smoke from forest fires over the Prairies drifting into southern Ontario,

Toronto’s air quality index was at eight, or “high risk,” this morning. Environment Canada says reduced air quality can cause mild eye, nose and throat irritation while more serious but less common symptoms include chest pains and a severe cough.