Feeling sick? The do's and don'ts to help you get better and protect others when you have a virus

Winter's arrival and the drop in temperatures that come with it means it's a good time to take stock of what to do – and what not to do – when you're feeling sick.

Colds, influenza and other respiratory illnesses tend to be more common during colder months, when viruses spread more easily because people are indoors more and in closer proximity to others. So far, doctor's offices and hospitals across the U.S. have been busy, said Dr. Trish Perl, a professor of internal medicine at UT Southwestern Medical Center. Physicians at the Dallas hospital have been "quite active," she said, and not just with cases of respiratory syncytial virus, or RSV.

"There's an increasing amount of influenza going around," she said. "Even in the past week we have seen the numbers increase, although it is unclear the trajectory, and it's notoriously unpredictable when it emerges."

The coronavirus that causes COVID-19 also tends to spread more during colder months.

Emergency room visits and hospitalizations for the flu, RSV and COVID-19 have been elevated or increasing in recent weeks, according to the Centers for Disease Control and Prevention.

If you come down with a respiratory virus, here's some advice from medical experts that can help you feel better and protect others.

DO: Stay hydrated.

Blood is comprised of 55% plasma and 45% cells. Blood plasma is made up of over 90% water, and a healthy blood pressure is important to deliver oxygen and nutrients throughout the body.

Drinking water helps your immune system by circulating blood volume, said Dr. Pei-Ni Jone, a pediatric cardiologist at the Ann & Robert H. Lurie Children's Hospital of...