[isaacfrond]

tl;dr

Cold air can damage the immune response in the nose, which is why people tend to get more colds and flu in the winter, according to a new study published in The Journal of Allergy and Clinical Immunology. "Cold air is associated with increased viral infection because you’ve essentially lost half of your immunity just by that small drop in temperature," said rhinologist Dr. Benjamin Bleier. The study found that reducing the temperature inside the nose by as little as 9 degrees Fahrenheit kills nearly 50% of the billions of virus and bacteria-fighting cells in the nostrils.