TENS of millions of people in North America woke up to warnings of dangerous air quality levels today as intense wildfires continued to blaze through Canada.

The intense Canadian wildfires are blanketing the north-eastern United States, including New York City, and parts of eastern Canada, with the haze turning the sky yellow and prompting warnings for vulnerable people to stay inside.

Environment Canada issued its strongest air quality warning for Ottawa on Tuesday, calling it a “very high risk” to health.