Wildfire smoke from northwestern Ontario and northern Minnesota has created hazardous air quality conditions across the U.S.Midwest, prompting health warnings and disrupting daily life.

The smoke, carried by high-pressure systems, has reduced visibility to less than a half mile in some areas and led to 'hazardous' air quality alerts in cities like Detroit, Chicago, and St.Paul.

Health officials warn that microscopic particles from the smoke can penetrate lungs and bloodstream, increasing risks of respiratory, cardiovascular, and neurological issues.In New York City, a thick haze obscured the skyline, with officials advising residents to limit outdoor activity and use air-conditioned spaces.Masks were distributed, and schools, parks, and events were moved indoors.The situation could persist for weeks as winds continue to transport smoke from ongoing fires.A study linked long-term exposure to wildfire smoke to thousands of annual deaths in the U.S., highlighting the severe health impacts of prolonged exposure.