MILWAUKEE - This week, the words "wind chill" are being ingrained into our heads. 

They describe how cold we feel, which isn't necessarily the exact temperature outside.

How can that be?  What exactly is wind chill?

"The perceived temperature on your skin of the temperature outside when the wind is blowing," explains Storm Team 4Caster Craig Koplien.

"Your body is constantly generating heat from the inside, and releasing it off your skin. When the wind blows, it takes the heat away from your skin faster than when there's no wind, so your body thinks that it's colder and needs to work harder to regenerate that heat as it's being transported away from your body faster, the faster the wind blows."

Wind chills only affect people and things that actually generate heat, not things that simply stand there like cars or most outdoor objects.

"The wind will cool things faster, but because a car, for example, that's turned off won't get any colder than the actual temperature because it's not generating any heat, but if it's running, and if you're heating your house, the stronger the wind's blowing, the faster the heat will be transported away from something that is generating heat internally," says Koplien.

"If it's something with an inanimate object that's not generating any heat, then wind chills really not a factor there."