This lesson on the cold and flu in teens explains how "lifestyle choices," such as diet and how much sleep a person gets, can affect the immune system and increase the chances of getting a cold or the flu. The lesson defines what a cold is and what the flu is, and the difference between the two. It gives the symptoms of each, how to avoid catching either a cold or the flu. It also advises on when a person should seek help from a doctor. 3 activities included and an assessment and answer key. cl