As we await the peak season for the H1N1 virus, one simple act may prevent the spread of infection: washing your hands. According to new research in the journal Risk Analysis, one-third of the risk for H1N1 infection comes from hand-to-face contact. We talk with Tara Parker-Pope, who writes the “Well” column for the New York Times, about why the routine act of washing your hands can have such big consequences for public health.