It’s cold across the U.S., and yes, it's winter, but this sort of cold snap will deliver record lows, miserable weather, lots of snow, wind chills and beyond-freezing temperatures. But what is this cold snap called? Meteorologists say it is the result of a "polar vortex" that is sweeping the nation.

A polar vortex is an enormous cyclone of dense, frigid air that usually disturbs only the North and South Poles, and the arctic temperatures it brings normally do not reach highly populated areas like the U.S. This sort of weather is unusual, and I’m sure even the polar bears would think it was cold today, especially in the Midwest.

Suffering the worst is the Upper Midwest. Minnesota and the Dakotas woke up to temperatures of 20 degrees below zero. But on Monday and Tuesday, every state but Hawaii will be suffering in freezing conditions. Twenty-six states are under warnings or watches for severe wind chill during the coldest weather the country has seen in 20 years. 

The National Weather Service is describing this cold snap as “life threatening” and already 13 people have died in the past week from weather-related incidents or causes. Frostbite and hypothermia are threats, so layer on the clothing people, and be safe when traveling, if you must.

Experts are predicting that the weather will ease in the next few days. So until then, keep warm, dry and hydrated, as Mother Nature shows just how unkind she can really be.