Sometimes when I'm coming up with lunch notes it helps to think like a child would think. (Believe me...that's easy for some of us!)
That's a perfectly logical train of thought describing a perfectly illogical name for an illness. And I can totally see my 4 year old coming up with that, or my 10 year old jokingly asking the question. I'm not automatically cold when I have a cold, and being out in the cold can't cause a cold on its own, so it just doesn't make sense.
Which is another reason I feel sorry for people trying to learn to speak English!