Millions threatened by 'dangerously cold' wind chills

High winds are making already frigid temperatures even more miserable across the Northeast and Midwest on Saturday.

State officials are urging residents to limit the time spent outdoors saying it's "dangerously cold" and warned them of blowing snow.
Cities like Minneapolis and Boston are set to reach below zero degrees Saturday and with low wind chills, some areas could feel as low as minus 40 degrees, the National Weather Service said.The snow is done but the cold temperatures are here to stay for the foreseeable future," CNN meteorologist Derek Van Dam said.
In photos: Brutal cold torments the US
The powerful Nor'easter or "bomb cyclone" that left the parts of the US resembling an icy tundra is to blame for this weekend's dangerously cold weather.
It dumped more than a foot of snow across eight states, deluged streets in Massachusetts with icy water and is now bringing extremely strong northwest winds and frigid arctic air to the US.
Over 110 million people are under a wind chill warning or advisory stretching from the Great Lakes to New England on Saturday, CNN meteorologists said.
Forecasters say the brutal cold will make Saturday the coldest day of the weekend before a gradual warm trend begins Sunday making temperatures rise.
What is wind chill?
It's the perceived temperature that people and animals feel when exposed to the elements. Or as forecasters say, it's the "feels like" temperature.
"As wind increases in speed, it increases the rate of heat loss on your body making you feel colder than it actually is," Van Dam said.
Wind chill is calculated by the rate the body loses heat due to speed winds and cold temperatures.
Saturday's cold snap has been called dangerous because it will make it easier for people to experience hypothermia and frostbite.