Video. Health experts are urging people to take precautions as wildfire smoke from Canada blankets New York City. They recommend limiting time outdoors, wearing a properly fitted N95 mask when necessary, keeping windows closed and using HEPA air purifiers to reduce exposure.

New York City has been dealing with a "Code Red" due to the heat and air quality advisories from Canadian wildfire smoke days before the Spain-Argentina World Cup final.

Wildfire smoke is dense enough in a handful of states that experts recommend masks for those who can’t stay indoors.