Downtown Chicago is seen through ice-covered trees in Northerly Island of Chicago, the United States, on Jan. 18, 2018. (Xinhua/Wang Ping)

WASHINGTON, Jan.29 (Xinhua) -- A polar vortex descended on the United States this week, freezing much of the Midwest and New England region.

Temperature will drop to minus 54 degrees Celsius in the Minneapolis-St. Paul region from Tuesday to Thursday, while the city of Chicago is expected to undergo windchill temperature of minus 48 degrees Celsius on Wednesday, according to the U.S. National Weather Service.

Weather experts are warning people to stay inside as the extreme cold can cause frostbite and hyperthermia in a matter of minutes, and deaths related to the cold have been reported.

As the extreme weather system stretches from the Midwest to New England, over 50 million people will be affected.

On Monday nearly 2,000 flights have been canceled across the country, and on Tuesday the number is expected to exceed the previous mark.

Hundreds of schools and government departments are closed in the states hit by the vortex.

The weather system is expected to lift by Friday.