Trying to answer another question about the link between the winter temperatures and catching the common cold, I remembered something one of my tutors said, namely that 'we catch more viruses when it is cold because our noses run and the exposed mucosa is a perfect virus catching ground' or something to that effect. So

  1. does a cold temperature make our nose run?
  2. does it mean we 'catch' viruses more easily this way?

To be honest, I can't find any evidence of my tutor's theory except for the runny nose being the symptom of an infection, not the cause...

  • 1
    By the way: Just considering it from an evolutionary point of view: Why do our noses run if it increased our risk of getting infections? And why didn't my nose run when I was visiting death valley (dry air)? ;-)
    – Philip
    Mar 5, 2011 at 22:27

2 Answers 2


As the Wikipedia article on mucus states, cold weather does cause runny noses:

During cold weather, the cilia, which normally sweep mucus away from the nostrils and toward the back of the throat (see respiratory epithelium), become sluggish or completely cease functioning. This results in mucus running down the nose and dripping (a runny nose). Mucus also thickens in cold weather; when an individual comes in from the cold, the mucus thaws and begins to run before the cilia begin to work again.

Mucus also functions as a trap for bacteria and viruses (again, quoting Wikipedia):

A major function of (mucus) is to protect against infectious agents such as fungi, bacteria and viruses. ... In the respiratory system, mucus aids in the protection of the lungs by trapping foreign particles that enter it, in particular, through the nose, during normal breathing.

I don't have any source on this, but I should think that a runny nose would be no better or worse than a dry nose for protecting against viral infections. If anything, I think it would be better to have a runny nose, as bacteria and viruses would have to "swim upstream" to reach their target destination.


You catch viruses more easily with dry mucosa. A running nose not only wets your mucosa but it also helps you transporting all the bacteria out of your body.

Rhinoviral infections in the winter are more common because people are more crowded indoors. That makes it easier for viruses to spread. And yes, you can even get a cold in the summer...

  • 1
    Do you have a reference for the dry mucosa/virus catching statemnt? that's really interesting :). btw: The connection between indoors and spreading is implied, but as far as we could come up with, not proven. See the cold/temperature question for more on this: skeptics.stackexchange.com/questions/88/…
    – Nanne
    Mar 5, 2011 at 22:11
  • No ;-) At least that's what I believed up to this point, though a quick Google search even suggests the opposite: medicalecology.org/pdf/presentation/Influenza.pdf (page 25) Though I have doubts about the reliability of this source...
    – Philip
    Mar 5, 2011 at 22:22
  • -1 for lack of source
    – Borror0
    Mar 5, 2011 at 22:38

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .