That old wives' tale about catching a cold in the cold may have some truth to it, according to new research out of Yale. While the common cold is still caused by viruses and not actual cold temperatures, it turns out that our immune systems become weaker when our noses are colder, thereby giving rhinoviruses—one of the more common types behind the common cold—more opportunity to thrive. Specifically, certain cells secrete chemicals that help both detect and fight infection, and these simply don't work as well in colder noses, reports CBS Local.
The researchers add that the story is more complicated and could involve other factors, including changed human behaviors in colder weather—such as staying indoors in closer proximity to other humans. Either way, the latest research could shed light on why rhinoviruses choose to infect the nose, which tends to be colder, instead of, say, the lungs: "This could explain why the rhinovirus causes colds and is less able to cause more serious lung infections, like influenza does," one researcher not involved in the new study tells the BBC. (Check out this deadly cousin of the common cold that showed up in France last year.)