A polar vortex dipping down from Siberia will bring a cold front with frigid temperatures to nearly 300 million Americans. See maps of the arctic blast.

An arctic blast will send temperatures across the United States plummeting as bitterly cold air that originated in Siberia will arrive from Canada by week’s end, bringing with it dangerously cold wind chills for millions of Americans.

Phil Badgett, a meteorologist at the National Weather Service Forecast Office in Raleigh, told The News & Observer in a phone call. Breezy winds on the forecast Tuesday night and Wednesday morning will make it feel colder than the actual temperature,

The Mississippi Department of Transportation is preparing its snowplows, just in case. It also is ready with sand and slag — a rock mixture — that it can drop on roads for traction over slippery ice. “All of our maintenance officers are stockpiled,” said David Kenney, a public information officer for the agency. “They’re ready to go.”