Everyone has heard the phrase "you'd better bundle up so you don't catch a cold." But I've always thought it was a misconception that being cold causes a person to catch a cold.

I recently got into an argument with a friend of mine on this issue. I insisted that the common cold is a virus, and that being exposed to cold air does nothing to infect a person with this virus; therefore, cold air does not cause people to catch cold. My friend said while that may be true, cold air makes people more prone to catching illness, therefore it could be said that cold air indirectly causes people to catch a cold. I had never heard that before and I had no idea how to respond.

So I need some clarification here. Does being exposed to cold air cause a person to catch cold? I'm sure OOT has the answer.