Everybody knows what it's like to wake up with a cold. You feel groggy, congested, and exhausted. In a perfect world, you could sleep the day away. But if you do that, your boss won't be happy. After all, you're not in grade school anymore, so when is it acceptable to call in sick to work?

Could It Be Contagious?


On average, adults get two to four colds a year, according to the American Lung Association. But one-third of companies offer no sick leave, a 2006 study by the Society for Human Resources Management reports. Typically, employers discourage sick days, unless their employees run the risk of infecting others.

"I truly believe you have to be in the position where you are helping people by not coming in," says Valerie Zimmerman, human-resources coordinator at National Fuel Gas Company in Williamsville, N.Y. "If you can still perform your job without the risk of getting other people sick, then you should be at your job."

Assessing Your Symptoms


It should be simple: If you could infect others, you should take a sick day. But because colds are so common, employers and employees often ignore them. How do you know if your condition is contagious? In general, experts agree that if you have a fever of more than 100.5, a productive cough, pain when coughing or speaking, or can't breathe through your nose, it's best to take a sick day.

A cold and the flu are alike in many ways, but the flu is characterized by a more sudden onset of severe symptoms. Telltale signs include tiredness, fever, headache, and major aches and pains, according to the Department of Health and Human Services. If you do have the flu, which can be highly contagious, you'll be doing yourself—and the entire office—a favor by staying home.

You Can Still Be Productive


What if you're under the weather but capable of going to work? It doesn't mean you can't be productive; it all depends on your job. Common colds are treatable with over-the-counter medications, eliminating the excuse to stay in bed all day.

"[Sick employees] can focus on certain aspects that they are capable of doing," Zimmerman says. "For example, I have a cold right now, so I shouldn't do interviews, but I can get a lot of work done at my desk."

Don't Catch It--or Pass It On


General work etiquette can help keep workplaces clean and reduce employees' chances of getting sick. Illnesses like cold and flu are spread primarily through coughing and sneezing, so workers should follow a few rules of thumb to reduce everyone's risk.

First and foremost, always cover your mouth and nose when coughing or sneezing, and wash your hands often. Remember to clean surfaces with a germ-killing disinfectant, and don't touch your eyes, nose, or mouth, which can encourage germs to enter the body. In addition, a flu shot can greatly lower a person's chance of getting the flu, according to the Centers for Disease Control and Prevention.

It comes down to common sense and respect for your coworkers, Zimmerman concludes.