I was recently hiking in mountains with some colleagues after a business trip. None of us had proper gear for 2000m, and consequently were rather cold. Now, all of us have advanced degrees in technical disciplines, so I was surprised to hear one of my colleagues suggest that we were likely to catch a cold as a result of this. I was even more surprised when the others agreed, and even claimed it was "common knowledge" and proposed the following mechanism of action:
- You are exposed to rhinovirus at some point, but your immune system is strong and overcomes it (mostly). Possibly it is asymptomatic at this point.
- The rhinovirus, defeated, takes up residence in your bone marrow, or perhaps somewhere else (DNA of other cells was suggested). It is suppressed, but not destroyed, and continues to attempt to spread.
- Exposure to cold temperatures or other stimuli weaken your immune system.
- The cold virus is able to resurge and you get the symptoms of a cold.
To be clear, the claim is that the cold weather causes the symptoms of a cold where one would otherwise not have experienced them.
To me, this sounds like a post-hoc justification for an old-wives' tale, but they insisted there was proof for this claim. What I'd like to see is a proper medical study on the question, or at least on the mechanism of action.
I want to note that this is not quite the same claim as the one being made in this question, which discusses the possibility of getting a cold after being cold. The answers there do not address the specific scenario outlined above, where one is first exposed to the virus, but the virus doesn't produce detectable symptoms until after the exposure to cold weather.