Temperature and Flu

"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. A respiratory virus or bacteria invades the nose, the main point of entry into the body. Immediately, the front of the nose detects the germ, well before the back of the nose is aware of the intruder, the team discovered. At that point, cells lining the nose immediately begin creating billions of simple copies of themselves called extracellular vesicles, or EV's. "EV's can't divide like cells can, but they are like little mini versions of cells specifically designed to go and kill these viruses," Bleier said. "But we found is that when you're exposed to cold air, the temperature in your nose can drop by as much as 9 degrees Fahrenheit. And that's enough to essentially knock out all three of those immune advantages that the nose has,"Bleier said.