The experts says it has nothing to do with cold weather; studies of scientists traveling to the Arctic proved that. But it is related to the time of year. Throughout winter, children assemble in schools, outdoor activities move indoors and we gather in large groups as the holidays arrive. This close contact during cold months, when we spend far more time inside with the windows closed, creates an environment for the spread of cold viruses.

"During this time of year, people are more apt to have close contact, kissing and hugging each other, shaking hands more frequently and sharing food," explains St. Louis University's David W. Bentley, M.D.

Once a virus is passed along from person to person, it runs its course until the season changes. When spring comes along, people generally have less close contact and spend less time indoors.