Infants and young children get more colds than adults — typically six to 10 a year — and are more likely to run a fever and to suffer cold-related complications that require doctor visits. Children, along with the elderly, smokers, and individuals with serious health problems such as asthma, heart disease, cancer, or chronic obstructive pulmonary disease (COPD), tend to suffer longer when they get colds.

When Is It More Than a Cold?

If your cold lasts much longer than two weeks or keeps coming back, allergies, sinusitis, or some other secondary infection may be the culprit. “Fever is an important sign,” says Norman Edelman, MD, senior scientific advisor for the American Lung Association. “Colds usually aren’t associated with fever.” Adults with a fever of 102 F (39 C) or higher and children with a fever of 103 F (39.5 C) or higher, should see a doctor, Dr. Edelman advises.

Serious Complications of the Common Cold

Colds can wear down your body’s natural defenses, leaving you vulnerable to health issues ranging from ear and sinus infections to strep throat, bronchitis, and pneumonia. Headaches, fever, and sinus pain could point to a sinus infection that requires treatment. “Certainly if you’ve had a cold or sinus infection and now you’ve got a worsening headache and a fever, that needs to be seen,” says David Ross, MD, an emergency medicine physician at Penrose-St. Francis Health Services in Colorado Springs, Colorado. If you have symptoms such as stabbing pains in the chest, a cough that brings up colored sputum, fever, or shortness of breath you may have pneumonia and should see your doctor. If symptoms came on fast, you should seek immediate medical care, Dr. Ross says. Respiratory syncytial virus, or RSV, is a common respiratory virus that shares symptoms with the common cold but can cause severe symptoms in infants, young children, and older adults. While most people recover from RSV infection in one to two weeks, the virus is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in U.S. children under 12 months of age. Signs of breathing difficulties in infants include flaring nostrils, breathing faster than usual, straining muscles in the neck, or bluish discoloration around the lips and on fingers. “If you see those things, bring them to the emergency room right away,” Ross says.

Checklists of Cold Symptoms to Watch For

Of course, most colds will never require an emergency room visit. But if the signs and symptom are looking questionable, it’s worth a trip. According to the American Academy of Family Physicians, here are some red flags to look for. In children:

High fever (above 103 F), or a fever that lasts more than 3 daysSymptoms that last more than 10 daysTrouble breathing, fast breathing, or wheezingBluish skin colorEarache or drainage from the earChanges in mental state (such as not waking up, irritability, or seizures)Flu-like symptoms that improve, but return with a fever and a worse coughWorsening of chronic medical condition

In adults:

A high, prolonged fever (above 102 F)Symptoms that last for more than 10 days or get worse instead of betterTrouble breathing or shortness of breathPain or pressure in the chestFainting or feeling like you are about to faintConfusion or disorientationSevere or persistent vomitingSevere pain in your face or foreheadHoarseness, sore throat, or a cough that won’t go away after 10 days