Minnesota effectively ground to a halt Tuesday as the lowest temperatures in a generation forced the state into a deep freeze.

Windchills plunged to 50 below in some areas, more severe conditions than those at the South Pole this week, with Wednesday shaping up to potentially be worse. The extraordinary weather manifested itself in frostbite cases at local hospitals, stalled cars and broken furnaces. Grocery stores, museums and many other businesses shut their doors, while prep sports events and some Capitol hearings were postponed.

Utilities struggled with the cold and wind, leaving several thousand people without power in the metro area. In Rochester, all transit service was suspended.

Even the Postal Service, which boasts of delivery in all weather in its motto, cried uncle and canceled mail delivery for Wednesday.

In some cases there was no stopping business as usual, such as the three steaming newborn calves born at Chris Schueler's dairy farm in Willmar, Minn. Time was of the essence to towel-dry the calves — fresh from a 100-degree womb — and hurry them to a warming area in a tractor bucket, lined with paper to prevent sticking.

"The cow literally can't lick them off quick enough before they get cold," Schueler said.

The frigid conditions can quickly take a similar toll on people. Regions Hospital in St. Paul and Hennepin Healthcare (HCMC) in Minneapolis have together seen more than 40 frostbite cases since last Friday.

Dr. Andie Rowland-Fisher, an emergency physician at HCMC, said the first sign of frostbite is pain in exposed areas, followed by numbness or tingling — then eventually no feeling at all. It can set in within minutes in the temperatures expected Wednesday, she said.

"If you think that you are getting frostbit … get in and get checked out because the treatments are time-sensitive," Rowland-Fisher said.

Rochester police also confirmed Tuesday a death linked to the cold wave, citing hypothermia as the likely cause based on preliminary autopsy results on Ali Gombo, a 22-year-old man who died early Sunday. Authorities said Gombo was discovered on the back deck of his sister's home — where he had been living — after being dropped off there without keys.

The deep freeze extended well beyond the state's borders, stretching its icy grip across a wide swath of the country from Montana to New York.

Mark Seeley, a University of Minnesota climatologist, pointed out the depth of the cold by contrasting the state's windchills with those expected at the South Pole this week, which are 20 to 30 below.

Furnaces under strain

The cold Tuesday was powerful enough to snuff out some furnaces and water heaters around the metro. Zach Erickson, owner of Erickson Plumbing, Heating & Cooling in Blaine, said calls about no heat were climbing.

Erickson said the outage is often due to an exhaust freezing over with ice.

"When the weather gets this cold it causes issues that aren't normal," Erickson said. "Basically just … any kind of condensation getting out of the building just — poof — turns to ice."

A more perilous situation — power outages — surfaced Tuesday night, with Xcel Energy reported about 7,000 people without power in the south and southwest metro. The utility blamed an equipment failure, which crews were working to repair.

Rick J. Smith from south Bloomington was starting to make reservations at a local hotel to keep warm, but the power kicked on at 10 p.m. after four hours.

The temperature had dropped to 60 degrees, Smith said, expressing worry for his neighbors. "We have an aging neighborhood and even a group home with six or seven mentally disabled not far."

While Michigan and Wisconsin have issued a state of emergency due to the cold, Gov. Tim Walz said Tuesday he does not have a similar plan. Wisconsin Gov. Tony Evers also activated the National Guard to help local responders as needed.

Walz said he has asked local government leaders to stay in touch with state officials and let them know if they need assistance.

"At this point in time, no local officials have asked for that," he said.

Walz is allowing local school districts to make their own decisions about whether to hold classes.

"One of the things I'm concerned about is when you close a school, sometimes that is the place of warmth and food that is not available elsewhere," Walz said, adding that local officials often know best what's right for their students.

Extra precautions set

Other precautions to keep people safe were outlined by Eric Waage, Hennepin County's director of emergency management, in a presentation to the County Board Tuesday.

Waage said Metro Transit stations will remain open all night and bus and light-rail riders will be able to stay on beyond their stops. Ambulances have put outdoor calls as a priority, he said, and the Hennepin County Sheriff's Office has increased patrols to check for people who might be stuck outdoors or living in vehicles. Fire departments are on high alert for calls about stalled vehicles.

There hasn't been a surge in electricity use due to increased heating needs, he added. Utility companies have asked their larger customers to use reserve oil supplies instead of gas, which is being used by smaller residential customers.

He said the county has had several water main breaks, and they expect more to come as the temperatures continue to drop. The county has teamed up with Twin Cities Public Television to run weather safety messages.

Some cities like St. Louis Park canceled garbage pickup, but in Minneapolis it is carried on as normal — with extra crews to allow people to warm up.

But for all its severity, the cold could also do some good before it leaves. The freeze will likely kill many invasive emerald ash borer larvae which have been chewing through the state's ash trees.

Research after the last polar vortex in 2014, when temperatures reached 20 below, showed that 60 to 70 percent of the ash borers died, said Jeff Hahn, an extension entomologist at the University of Minnesota. The death rate will be greater at 30 below — perhaps up to 90 percent.

"They're not all going to die. We're not quite that lucky," Hahn said.

Staff Writers Jessie Van Berkel, Paul Walsh, David Chanen, Matt McKinney and University of Minnesota student Isabella Murray contributed to this report.

Correction: An earlier version of this article incorrectly indicated that all State Capitol hearings were postponed. Some hearings are postponed, others are being held.