People have been telling their loved ones to “bundle up or you’ll catch your death of cold” since forever, and now, science might have found a connection between frigid temperatures and illness after all.

This discovery explains the biological mechanism behind the reason certain viruses see seasonal spikes – which could also help us figure out how to prevent them.

Dr. Benjamin Bleier, director of Otolaryngology Translational Research at Mass Eye and Ear issued a statement on their results.

“Conventionally, it was thought that cold and flu season occurred in cooler months because people are stuck indoors more where airborne viruses could spread more easily. Our study however points to a biological root cause for the seasonal variation in upper respiratory viral infections we see each year, most recently demonstrated throughout the COVID-19 pandemic.”

It turns out that when the temperature drops, our noses drop the ball.

Our first line of defense against pathogens exist in our nasal cavities, in the swarms of extracellular vesicles (EV) that are released there to capture and attack the foreign virus.

Research found that people who were exposed to temperatures of 40 degrees F for 15 minutes saw a corresponding drop of the temperature inside the nose (of around 5 degrees).

They also found that this drop in temperature impaired the EV’s response to a pathogen, cutting their numbers by almost 42%.

Those that were loosed on the invader also showed impaired antiviral proteins, explained Mansoor Amiji, Distinguished Professor of Pharmaceutical Sciences at Northeastern.

“We’ve uncovered a new immune mechanism in the nose that is constantly being bombarded, and have shown what compromises this protection. The question now changes to, ‘How can we exploit this natural phenomenon in the nose and boost this protection, especially in colder months?'”

No answer yet, but I think I might start covering my nose when I go out in winter.

Just in case.