MILWAUKEE (CBS 58) -- Fingers, toes, and your nose are the first body parts to feel the burn in this extreme cold but your lungs could also be at risk. 

Despite this cold weather, there are always people who have to work outside no matter what such as bicycle couriers.

"It's just like any other job in the cold, just gotta keep moving and stay warm," said Kevin Ward.

Ward says wearing lots of layers is how he keeps going.

"If they say there's a wind chill advisory, we have to add 10-15 degrees more than that."

Chris Zinc layers too while dodging the wind by ducking into buildings. 

The American Lung Association says a scarf is one of the most important pieces of clothing to wear in this weather because cold air can be hard on the lungs.

"If you're outside, cover up the nose and the mouth because what you want to do is warm up the air going into your lungs," said Dona Wininsky, Communications Director for American Lung Association.

They also say to keep an eye on air quality forecasts. If you have asthma, keep medication handy and avoid fireplaces because fumes can cause irritation.

"The cold air, it can irritate the lung tissue. It can cause your lungs to spasm similar to what happens during an asthma attack," Wininsky said.

Will these hazards stop messengers from moving around Milwaukee? The ones we talked too said no.

The American Lung Association says you should make sure to have a working carbon monoxide detector and check on teh elderly, especially those with lung and/or heart problems.