Dangerously cold air has sent temperatures plummeting into the single digits around the U.S., with wind chills driving them even lower. Throw in the snow some areas are getting and you've got a bone chilling mix that may also be super messy.
School delays and cancellations, a fatal car pileup and worries about the homeless.
Here's a look at what's happening:
DELAYING AND CANCELING SCHOOL
School districts from the South to the Northeast and Midwest delayed the start of classes or canceled school altogether.
Wind-chill readings were at or below zero in such places as Alabama and North Carolina, along with a chunk of the Midwest, the Plains and the Northeast. The wind chill was minus-40 in Saranac Lake in upstate New York on Thursday morning.
In northwest Georgia, schools in Catoosa County had a two-hour delayed start on Thursday because of temperatures expected to top out at 27 degrees and dip as low as minus 2 degrees with wind chills.
Many other cities modified school schedules, including Detroit, where it was 3 degrees early Thursday. Students got the day off Thursday at Detroit Public Schools, the state's largest district, and at many other districts around Michigan.
School districts also closed schools in Illinois, Indiana, Kentucky, Tennessee, Alabama, Pennsylvania and Maine.
DEATHS IN MICHIGAN
Authorities say the severe weather and blowing snow are factors in the deaths of two northern Michigan men - an 85-year-old who was struck by a car while crossing a road to get his mail and a 64-year-old who was hit by a car while clearing snow.
A car struck 85-year-old Carl Dewey on Wednesday in Helena Township, about 30 miles northeast of Traverse City, the Antrim County sheriff's department said. There were whiteout conditions at the time, the department told The Grand Rapids Press.
The Kalkaska County sheriff's department said 64-year-old Zane Chwastek of Bear Lake Township was using a snow blower in his driveway Wednesday when a car slid off the road and struck him.
A PILEUP IN WHITEOUT CONDITIONS
An 18-vehicle pileup that happened in whiteout conditions on a western Pennsylvania interstate left two people dead and nearly two dozen injured.
Nine trucks, several of them tractor-trailers, and nine cars were involved in the crash Wednesday afternoon on Interstate 80 in Clarion Township, state police said. At least one of the trucks was carrying hazardous material, but no leaks were found.
None of the injuries was thought to be life-threatening, but three of the approximately 20 people taken to the hospital appeared to have serious injuries. The others were treated for everything from bumps to broken bones.
HORSES KILLED IN FIRE
A space heater being used to thaw frozen pipes was the likely cause of a barn fire that killed more than a dozen horses in northern Ohio, fire officials said.
"It just engulfed the building. It went up in a hurry," said Tim Kelly, an employee of the farm in Tallmadge, a suburb of Akron. "By the time you saw it, the building was just full of smoke with flames just coming through the roof."
Firefighters were hindered by temperatures hovering around 3 degrees.
"We went in, but you couldn't see and you couldn't breathe," Kelly told the Akron Beacon Journal. "You could hear them, but we couldn't get them out."
Below-freezing temperatures in the nation's capital caused headaches for commuters.
In all, there were delays on five of the Metro system's six lines Thursday morning.
The Washington transit agency says the system's red line was delayed in both directions because of weather-related equipment problems on train cars. The other four lines were delayed because of broken or cracked rails.
Commuters vented their frustration on Twitter, with many posts including photos of stations and trains jam-packed with people. One Twitter user wrote that he loves being told to avoid lines that have delays, adding, "OK, I'll just move my house and job for the day."
KEEPING RESIDENTS WARM
Many cities experiencing cold weather have opened warming stations for residents lacking heat. But extra care is being taken to protect the homeless.
In New Jersey, some officials have empowered law enforcement to move homeless people off the streets and into shelters.
Blankets were being given out at some of the 15 small tent cities around Huntsville, Alabama. Workers from a nonprofit organization there encouraged residents of the encampments to come inside. Some people planned to stay at a church that was opening as a shelter.
"We've got snow flurries as the temperatures continue to drop so they're coming in," said Clete Wetli, executive director of First Stop Inc., which provides transportation, mental health counseling and other services to the homeless. "The last thing we want is for someone to get hypothermia or die of frostbite."
Officials in Ohio and Georgia warned residents never to use their kitchen ovens or stoves to heat their homes. It could prove deadly.
A DOG'S TALE
A California couple is thanking animal control officers who rescued their dog after it spent 25 hours wandering in bitter cold after a housekeeper accidentally released the pooch from their Indiana hotel room.
The 3½-year-old Belgian Malinois named Sahara is back with Nick Hoeh and Rick Dunkle after her ordeal in Lafayette, Indiana, where the couple recently moved from California.
Animal control officers found the shivering canine Wednesday in a Lafayette resident's backyard following several sightings.
A hotel housekeeper accidentally released Sahara from the couple's hotel room Tuesday. The couple is staying at that hotel because a burst pipe damaged the new Lafayette home they had just purchased. The couple had saved Sahara from an abusive home.
GETTING WORSE BEFORE BETTER
Another Alberta clipper barreling down from Canada is bringing more bad winter weather to the Dakotas.
The National Weather Service has posted a variety of blizzard and winter weather advisories, watches and warnings for the Dakotas through Thursday. Not a lot of snow is expected, but winds gusting to 50 mph will blow around the snow that's on the ground.
In Minnesota, forecasters expect blizzard conditions to develop in a portion of the River Valley. Weather officials say wind gusts of 40 to 50 mph combined with fresh snow will significantly reduce visibility, especially in open, rural areas. A blizzard warning was posted in an area from Granite Falls southeast to Mankato and Albert Lea.
THERE IS A BRIGHT SIDE
Temperatures have dropped to zero or below in southern New England and to 7 above in New York City, with wind chills getting into the minus-20s in some places. But little or no snow is forecast for most of the Northeast.
Around this time last year, parts of the region were digging out from 2 feet of snow accompanied by brutal polar air.
In fact, this season's snowfall totals are way down from last year, one of the snowiest seasons on record.
Last year, Philadelphia, New York and Boston all got around 5 feet of snow from December through February, or about 1½ to 2½ feet more than normal. This year, they've seen only a few inches of snow since Dec. 1.
But then there's western New York. The Buffalo area got slammed with more than 7 feet of snow in November and saw another foot on Tuesday. Thursday night and Friday could bring another 5 inches to 10 inches, weather forecasters say.
MEANWHILE IN ARIZONA ...
Phoenix posted a record high temperature of 80 degrees on Wednesday. That broke the old record of 79 set in 1948.
Over in Tempe, 74-year-old Bill Justice was wearing shorts while hanging out in his yard, just days after the National Weather Service announced that 2014 was the warmest year ever recorded in Arizona.
"We can enjoy all kinds of things in the winter and the same thing in the summer," Justice said, adding that if he lived in Colorado or another cold climate, his swimming pool would be frozen by now.