Smoke from forest fires in the Prairies will affect southern Ontario Wednesday night, Environment Canada says. The statement came just as the weather agency lifted the city's fifth heat warning this year.

Environment Canada issued a special statement warning Torontonians to limit time outside where smoke is expected to create unhealthy conditions.

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.