The virus behind the common cold is much happier in a cold nose, US researchers suggest.
Their study showed the human immune system was weaker in cooler temperatures, allowing the virus to thrive.
The researchers suggested keeping your nose warm and avoiding cold air while infected.
Source: Common cold ‘prefers cold noses’
It’s likely to be much more complex than that. Dry air causing dry mucous membranes and skin which makes for easier portal of entry. Maybe change in activity or interactions of some animals that act as reservoirs. Probably a dozen other things… This study only focused on mouse cells growing in a culture dish. While they controlled for humidity and whatnot, but not at all in the context of an intact organism breathing in virus.