People have been coming to the city's warming centers for temporary relief from Chicago's deep freeze. It is important to stack layers when going outside, but there's a lot that can be done at home too to stay warm under a budget.
The extreme temperatures have also been creating all sorts of challenges and keeping repair crews busy.
The low temperature Thursday morning was five degrees with below-zero wind chills, making it the coldest day since February 20.
Friday morning will have wind chills below zero again.
It's the first bitter cold of the season, serving up frigid windchills.
WARMING CENTERS | SEE FULL LIST
"Why are we skipping an entire category going from 30 to 10? Spend some time in the 20s," commuter Bryan White said.
Trains blew up snow, as they pass by with piles of snow still covering the ground.
Train platforms were icy and slick in the western suburbs.
Commuters covered up as much of their face as possible with gloves, hats and scarves - the name of the game.
"I layered up pretty well," commuter Lee Ferron said. "Long underwear and a bunch of other layers."
"You gotta put on enough layers," commuter Trae Ferguson. "You might be all right for a few minutes, but I don't care how much you've got on, you don't wanna be out there too long. It's pretty cold."
People try to keep warm during deep freeze in Chicago area
The smart ones sought refuge inside the LaGrange Metra Station to stay warm, avoiding the chill, until the last second.
"It's the first day I'm actually standing in here," commuter Danny Mazzei said. "Before I was able to be out there and I forgot my beanie which is not great."
Over at the Horton's ACE Hardware, they recommend you stock up on things like ice scrapers and snow brushes before you need them or run into any weather-related issue.
"We have ice melt for both the ground and rooftops, and we have roof rakes for getting snow and ice down off the roof," manager Jeremy Magnusen said. "We have gloves because it is bitter cold out there nobody wants to be cold out there. They want warm hands, not cold hands. We also have some heating elements for heating your pipes anything you got close to outside in the wintertime."
And hey, if you have the option, not a bad idea to work from home.
"I am not pleased, but holiday party tonight so I've gotta go," commuter Bryan White said. "Otherwise I would definitely be staying at home today."
Doctors say minutes matter in the cold, when temperatures drop this low.
They see frostbite issues in the emergency room for fingers, hands and ears if people are outside for too long. That's why it's important to utilize any indoor space you can Thursday and, wear many, many layers.
"In my experience, people don't appreciate how fast frostbite actually happens. They think I can go get the mail, I can go walk my dog real quick and they don't realize that this can happen in a matter of minutes," Dr. Nicholas Cozzi of RUSH University Medical Center said. "We have to be particularly concerned about our young people, our kids, as well as the elderly, so check on your neighbor, make sure that your neighbor is doing well and ultimately we'll ride this out and we'll be OK, but you got to take care of yourself and your family."
The Office of Emergency Management and Communications is encouraging residents to stay indoors if possible, to limit time outside and to download the OEMC app.
"For our vulnerable communities, we want to make sure that they can call 311 for well-being checks if they need assistance with sheltering placement," said Matt Doughtie with OEMC. "Please limit your time outside. Limit your time on the roadways if possible."
To maximize the heat in homes, ComEd recommends weather-stripping windows and doors and leaving window blinds open during the day to let the sunshine in. Those simple things make a difference.
NIPSCO, the Northern Indiana Public Service Company, is also working to keep customers safe with a few early pointers, like using space heaters with caution, making sure all heating appliances are operating properly and never using a stove or oven as a source for heating your home.
"If you're experiencing any symptoms of carbon monoxide poisoning, which could be headaches, dizziness, nausea, vomiting, irregular breathing or even feeling ill or tired while at home, you want to make sure that you are calling, getting the appropriate medical assistance that you need, as well," said Joshauna Nash with NIPSCO.