Different from other common diseases, colds are not caused by bad weather. Colds are caused by viruses(病毒) in the body, and you are better out on the snowy day than in a warm room with your friends, who just may be passing the virus around. If you feel a chill(发冷) when you are coming down with a cold, you are always sick. （如果你感冒的时候感觉到冷，那你就得注意了）A chill is an early sign of the cold.
    The virus can spread（传播） through air when a cold-sufferer(感冒患者) coughs or sneezes(打喷嚏). Surprisingly, this is not the most usual way of spreading. Many studies have shown that most colds are “caught” by hands. A cold-sufferer rubs（摩擦） his or her nose, so spreads the virus to his or her hand. Then a friend comes to visit him or her, and they shake their hands. Then the friend gets something to eat by hand, and several days later he or she also catches a cold. Although some parents pick up their children’s tissues(纸巾) and carefully throw them away, they fail to wash their hands. They’ll catch the cold, too.
    Cold viruses can also be spread by objects,（感冒病毒也可以通过物体传播） for example, telephones, plates, and so on. The cold-sufferer and other members of the house, can stop the viruses from spreading in a way, by washing their hands often.