Deep freeze death toll climbs to 15 as dangerously cold temperatures paralyze much of US Record low actual temperatures were recorded in many Midwest cities.

A dangerous deep freeze is blasting the Northeast and Midwest, where record-breaking cold temperatures are paralyzing cities and communities.

The wind chill in Chicago plunged to minus 52 on Wednesday -- the coldest wind chill since 1985. It was minus 55 in Minneapolis, also the coldest wind chill since 1985.

Thirteen people have died in connection to the dangerously cold weather, according to The Associated Press.

University of Iowa student Gerald Blez, who was studying medicine, died Wednesday, the university said. His cause of death is believed to be weather-related, officials said, according to ABC affiliate KCRG. The wind chill at the time was minus 51 degrees, KCRG said.

In Milwaukee, Wisconsin, a 55-year-old man was "cold and frozen" when he was found dead in a garage near a snow shovel Tuesday, a medical examiner's office official said.

The latest temps

The bone-chilling temperatures are unrelenting in the Midwest, where the actual temperatures -- not wind chills -- remained in the minus 20s and minus 30s Thursday morning.

Two cities in Illinois -- Moline and Rockford -- hit their all-time coldest temperatures Thursday: a frigid minus 33 degrees and minus 31 degrees, respectively.

Cedar Rapids, Iowa, also set a new all-time coldest temperature of minus 30 degrees.

Record low actual temperatures for this date were recorded in Chicago Thursday: minus 21 degrees; Madison, Wisconsin: minus 26 degrees; and Milwaukee: minus 23 degrees.

In Michigan, Gov. Gretchen Whitmer on Thursday urged residents to turn down their thermostats "due to extremely high energy demand."

On the East Coast, New York City had a temperature of 2 degrees -- the city's coldest day in three years.

Philadelphia reached a temperature of 5 degrees with a wind chill of minus 11 -- the coldest so far this winter.

Boston also fell to 5 degrees with a wind chill of minus 16.

States left paralyzed

The weather is wreaking havoc on transportation.

Over 8,000 flights have been canceled in the U.S. since Monday. On Wednesday over 1,800 flights were canceled in Chicago alone.

In Buffalo, New York, where about 20 inches of snow fell, the airport canceled most of its flights Wednesday.

Lake effect snow is set to continue in western New York state with more than 1 foot of snow still possible.

In Ellisburg, New York, snow fell at a rate of 2 to 3 inches per hour on Thursday. Resident Ethan Richardson-Morris called shoveling the driveway "a constant battle." As soon as one side was shoveled, the other side filled up.

"I'm just trying to make it to so my dad can get in the driveway from work," he said.

Friday forecast

The core of the coldest air lifts north back to Canada by Friday but wind chills are still going to be very low.

Friday wind chills are forecast to clock in at minus 16 degrees in Minneapolis; minus 2 in Chicago; minus 7 in Detroit; minus 5 in Boston; and 0 in New York City.

Weekend warmth

By the weekend, some areas will feel like it's almost 100 degrees warmer than it is now.

In Chicago, where wind chills were in the minus 50s Wednesday, residents will warm up to temperatures in the 40s.

ABC News' Whit Johnson, Carlos Boettcher and Christine Theodorou contributed to this report.