Asthma episodes tend to surge in the autumn and winter, when people tend to get more colds. Even a mild case of the sniffles can make asthma harder to control. A viral infection is a common trigger of an asthma attack.
Cold viruses can survive for hours on doorknobs, handrails, and even money. Washing your hands often—at least every few hours—will flush away the viruses before they have a chance to take hold.