What effects does cold weather have on the lungs?

Cold air hurts lungs. Cold air is naturally dry. When you breathe cold dry air into your lungs, moisture from your bronchial tubes evaporate. This irritates the surface and can cause the bronchial tubes to spasm in people with asthma. There is a test to help diagnose asthma where patients are asked to hyperventilate breathing cold dry air. Breathing through a scarf or mask helps shield the lungs from the dryness.