BISMARCK, N.D. — More than 95 million people were facing gripping cold Tuesday as a polar vortex sends temperatures plunging to record levels, closing schools, bursting pipes and forcing communities to set up more temporary shelters for the homeless.

“Some of the coldest temperatures of the entire winter season right now across the central United States,” said Andrew Orrison, a meteorologist with the National Weather Service.

The harsh cold descended on the nation’s midsection Monday on the heels of weekend storms that pummeled the Eastern, U.S. killing at least 17 people. Some areas in the Midwest have wind chills as cold as minus 50 to minus 60 degrees, Orrison said.

It is so dangerous that hundreds of public school districts canceled classes or switched to online learning Tuesday in Oklahoma, Iowa, Minnesota, Nebraska, Wisconsin, Kansas and Missouri. The biggest batch of record-setting cold temperatures are likely to hit early Thursday and Friday, Orrison said.

— The Associated Press