Beijing issued its highest-level alert for smog levels today — a “red alert” — as the Chinese capital expects three or more days of severe smog.

Schools are closed, outdoor construction has stopped and driving restrictions are in place, the BBC reports. A statement from the Beijing Municipal Environmental Protection Bureau said even healthy people should try to avoid outdoor activity and take public transportation. The alert will remain in effect until noon on December 10, when a cold front is expected to clear the smog, the BBC says.

Even though current pollution levels in Beijing are lower than last week's, the alert was issued because of levels expected over the coming days.

It comes as China, one of the world's largest polluters, takes part in talks on carbon emissions in Paris. Last week China agreed to “reduce emissions of major pollutants in the power sector” by 60 percent by 2020, The Guardian reports. The country will also reduce annual carbon dioxide emissions from coal-fired power generation by 180 million tons by 2020, according to The Guardian.

Related: Air Pollution Kills More Than 3 Million People a Year, Study Finds

Wearing a face mask in BeijingA woman wears a face mask in Beijing, but health officials say these don't offer much protection from small particles in the air. (Photo: Greg Baker/Getty Images)

Many people are wearing face masks in an effort to breathe less of the polluted air. However, loose-fitting disposable masks do very little to filter or block small particles in the air, according to the Food and Drug Administration (FDA).

According to The New York Times:

“Many masks worn around Asia are simple surgical-type masks. But these are designed to prevent problems like splattering blood, not to block tiny particles, Benjamin Cowling, an associate professor of public health at the University of Hong Kong, said in an email. “It is pretty common knowledge that surgical face masks have almost no filtration efficiency against pollutants,” he said.”

What should you wear instead? Try a respirator mask that guards against at least 95 percent of small particles, experts say. Sometimes called N95 respirators, they’re tested by the National Institute for Occupational Safety and Health and must be shown to keep out at least 95 percent of all tiny airborne particles to gain approval. However, The New York Times reports, those respirators may make breathing more challenging for people with heart and lung problems. In those cases, it’s best to heed the advice to stay indoors.

Related: Indoor Pollution: How to Clear the Air

Angela is a Pulitzer Prize-winning digital editor with more than 15 years of experience delivering news and information to audiences worldwide. Prior to joining SafeBee, she was the features editor for at The Boston Globe, overseeing health, travel, entertainment, business and lifestyle coverage. Before moving to features, she was the news and homepage editor, covering stories such as the Boston Marathon bombing, Red Sox World Series victories, presidential elections, a papal inauguration, and more. Her favorite safety tip: Clean your phone! The average cell phone has 18 times more germs than the toilet handle in a men’s restroom.