Human Sinus

Cold Air

Breathing in cold air can trigger wheezing and nasal congestion. Sometimes this is a purely physical effect and happens in two ways: The entire respiratory system is coated with a thin mucus blanket. Cold air stimulates an increase in mucus production. In addition, the mucus becomes thicker in colder temperatures. When breathing through the nose, you may breathe in air at 40 or 100 degrees Fahrenheit, but within a quarter of a second, the air temperature is quickly brought to 98.6 degrees Fahrenheit. This is done by tiny blood vessels, known as capillaries, that function to bring about this temperature exchange. When a person breathes cold air in, the tissue lining the nose swell as the capillaries dilate, bringing warm blood to heat the cool air. Swollen capillaries in the nose are the cause of nasal congestion. In addition to the congestion the mucus in the nose increases and becomes thicker. This happens more in some people than in others.