Wildfire smoke has returned to midwestern Ontario.
Environment Canada has the region under a special air quality statement as the smoke from fires burning in the Prairies is expected to make air quality poor and reduce visibility on Thursday.
"Air quality and visibility due to wildfire smoke can fluctuate over short distances and can vary considerably from hour-to-hour," the national weather agency advised. "As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events."
The smoky conditions can commonly lead to eye, nose and throat irritation, headaches or a mild cough. In less common cases, the air pollution can cause wheezing, chest pains or severe cough. People most likely to be affected include seniors, pregnant women, small children, those with chronic illness, and outdoor workers.
Air quality should improve from north to south gradually throughout the day on Thursday.
Environment Canada recommends keeping windows and doors closed as much as possible until the smoke clears.
