Chicago faces a heat wave with poor air quality due to wildfire smoke and ozone; temperatures may hit mid-90s.

Windsor-Essex, Chatham-Kent and Sarnia-Lambton can all expect elevated air pollution levels again Tuesday. Environment and Climate Change Canada has once again issued a special weather statement for the region. This time, the weather office says weather conditions are expected to cause increasing levels of ozone.

Tuesday’s air quality warning has dropped to a 5, considered a moderate risk, down from Monday’s peak of 10+ on the Air Quality Health Index’s 10-point scale.

The poor air quality that has blanketed swaths of central and Western Canada is not only infiltrating the lungs, but also distressing the mind.

Dr. James Weber, lead author at the University of Reading, said, "The UK has made progress on air quality, but there is still a long way to go. Pollution from traffic is getting better, but we need both local action and international cooperation to improve ...

The Air Quality Health Index is expected to be as high as seven, or high risk, according to Environment Canada.