Google has told its employees in the northeast of the U.S. to work from home in order to limit their exposure to smoke drifting in from hundreds of wildfires in Canada.

Dramatic news images of New York City disappearing in a smoky haze on Wednesday showed the extent of the dire air quality as fires in eastern Canada continue to burn. Data later revealed that the air quality in the metropolis on Wednesday was the worst of any city globally.

“We are advising Googlers to work from home if possible, and limit their exposure to outdoor air,” Google said in an internal note seen by CNBC. “Terraces across our New York campus will remain closed today.”

The advisory notices were reportedly sent to workers in the Detroit area; Washington, D.C.; Reston, Virginia; Pittsburgh; and Raleigh-Durham, North Carolina. Employees in the Canadian cities of Toronto and Waterloo were also asked to work from home.

Since the pandemic, Google has allowed many of its staff to work remotely for up to two days a week, so it’s already set up for such scenarios.

And considering how Google has spent much of its existence building a burgeoning suite of cloud-based productivity tools, there can be few companies better placed to handle remote work.

The air quality in New York City is expected to improve slightly overnight but will likely worsen again on Thursday afternoon and evening.

The seriousness of the situation prompted New York City Mayor Eric Adams to recommend that the city’s inhabitants “limit outdoor activity to the greatest extent possible,” adding that those with preexisting respiratory problems, along with children and older adults, “should stay indoors at this time.”

Doug Ford, premier of Canada’s Ontario province, said on Wednesday that half of the forest fires in Ontario had been caused by lightning strikes while the rest were the result of human activity such as improperly extinguished campfires.