http://medlineplus.i2p/ency/article/000678.htm
A cold virus spreads through tiny, air droplets that are released when the sick person sneezes, coughs, or blows their nose. You can catch a cold if: A person with a cold sneezes, coughs, or blows their nose near you You touch your nose, eyes, or mouth after you have touched something contaminated by the virus, such as a toy or doorknob People are most contagious for the first 2 to 3 days of a cold.