DENVER (KDVR) — With temperatures expected to fall below zero this week, FOX31 spoke with the Chief of Medicine at National Jewish Health about how extreme cold affects your health.

“Someone who’s young and perfectly healthy probably has a little less to worry about than someone who might say, have a chronic medical condition,” Dr. Carrie Horn said.

Horn said cold air can put a strain on your lungs.

“That cold air hitting those lungs can really make them tighten up and make you feel short of breath,” Dr. Horn said.

Breathing in warm air, Horn said, is a relief for your airways.

“Making sure that you’re covering your nose and mouth and getting that warmer air when it goes into your lungs is really important,” said Dr. Horn.

Shoveling snow or taking a walk is technically cardio, and cardio in the cold can have an impact on your circulation.

“That can really put a lot of stress on your heart because it’s a lot of upper body and a lot of cardio and so that can be stressful for people who have underlying coronary issues.

Horn added another very important rule in the cold: bundle up!

“Any kind of exposed surface, you’re going to be losing body heat and your body is going to be trying to accommodate that as best it can,” Dr. Horn said.

If you’re exposed, without gloves or well-insulated shoes and socks, or if you’re wearing shorts, that cold air can strain your body’s ability to stay warm.

“The longer you’re outside, the harder of a time your body’s going to have to adjust to that, your body squeezes down its blood vessels to preserve your inner heat. In those areas, you’re going to be much more susceptible to that cold damage like a frostnip or frostbite,” Dr. Horn said.

Another tip, eating light or bundling up if you plan to have a large meal.

Dr. Horn said when you eat, blood vessels in your stomach expand so your body can digest food.

That could take much-needed circulation from the rest of your body to keep warm.