The polar vortex is an area of low pressure and cold air that swirls like a wheel around each of Earth's two polar regions. Sometimes the Arctic polar vortex wobbles and a lobe surges south, blanketing parts of North America with bitter temperatures.
"It depends. While you're dealing with subzero temperatures at the pole, it does modify, fortunately, as it comes further south," Pugh said.
But with the wind chill, temperatures can feel significantly more punishing.
"If you add just a little bit of wind, it can really make it feel so much more brutally cold," Pugh said. "It doesn't take a lot of wind once we get so cold for it to feel even worse. So while the temperatures are cold enough to begin with, you can add a little wind chill to make it absolutely bitter."
The polar vortex is separate from global warming and climate change.
"Climate change is not based on a single event like a polar vortex-induced cold snap," TODAY's Al Roker said. "It’s measured over a long period of time and government statistics, going back to 1880 when record-keeping began, show that on average, the world’s annual temperature has been ticking upward."
Climate change also hasn't affected the frequency of how often we experience the polar vortex or the temperatures associated with it, Pugh said.
"While some [other weather] events are signatures of a warming planet, this is not one of those events, and we do not give attribution to climate changes for the swings in the polar vortex," she said. "It's been a phenomenon that has been studied for decades now."