viruses live in mucus and saliva so always sneeze into a tissue or into your arm
keep your plans if coughing, sneezing, and stuffiness are your only symptoms, try to rest as much as possible
stay home if congested with muscle or joint pain, chills, fatigue, or a fever. temperature over 101? see doctor ASAP
why people get sick:
your body pumps out adrenaline to get you through crunch times, like exam week. This adrenaline can also decrease your body's T-cell levels, they are your best defense against illness.
parties may mean alcohol and exposure to smoke both which paralyze microscopic hairs in nose that keep germs out of airways. lack of sleep also lowers resistance to illness.
cold temperatures keep you inside where its warm and cozy, indoor heating systems dry out the mucus that washes away bacteria and viruses from nose and lungs, you're also cooped up with everyone else's germs too