It might sound lame, but if you are coughing and spluttering all day long, the infection in your mouth will get re-swallowed and re-spread throughout your throughout your system.
It is actually suggested to drink a lot of hot fluids on a regular basis, especially tea. Why? Because the virus stays in your nose and mouth for several days before making its way down towards the lungs. Drinking on a regular basis will wash down the virus towards your stomach where the gastric acid will kill it. So drink a lot throughout the day, whether you are healthy or sick.