I just love this article. If your mother was anything like mine (and I grew up in Chicago, which does get really cold in the winter), she would tell me not to get chilled, to zip up my coat, not go out with wet hair and so on.
Well, this article proves her to be right. British researchers found that if you already have a dormant cold in your system, getting a chill can retard the development of white cells which fight off colds, thus letting the dormant cold become active. Without the chill, it is possible you would not have gotten sick.
Barbara