The common cold and seasonal flu have similar symptoms -- both are contagious respiratory illnesses -- but there are a few key differences. A cold is generally milder than the flu, and the flu usually comes with a fever, aches and chills. Colds also come on slower, while the flu usually hits hard and fast. In young children, a fever may accompany their cold because their bodies aren't yet accustomed to fighting off infection without raising their body temperature.

The Centers for Disease Control and Prevention (CDC) lists common cold symptoms as: 

• Sneezing
• Runny nose
• Coughing
• Dry throat
• Mild body aches or headaches
• Watery eyes

Flu symptoms include:

• Fever (often high)
• Headache
• Extreme tiredness
• Dry cough
• Sore throat
• Runny or stuffy nose
• Muscle aches
• Stomach symptoms, such as nausea, vomiting, and diarrhea, also can occur but are more common in children than adults

 When to Call the Doctor:

If your child is 3 months or younger, call the pediatrician at the first sign of illness. For a cold in a child older than 3 months, the American Academy of Pediatrics (AAP) recommends calling the doctor if:

• Nasal mucus persists for longer than ten to fourteen days. William Sears, M.D. notes that if "discharge begins seeping from her eyes as well, it's time to see the doctor. Babies with the eye-nose combo may have both a sinus and an ear infection and likely need antibiotics to treat them."

• A cough persists for more than one week

• Your child has pain in his ear. This can be tough to discern since signs of ear pain aren't very clear, says Meg Fisher, M.D., the department chair of pediatrics and medical director of the Children's Hospital at Monmouth Medical Center in Long Branch, New Jersey. General irritability and fever can be indicators; tugging on the ear, while widely considered a sign of ear pain, is more likely done out of habit than ear discomfort, says Dr. Fisher.

• For diarrhea and vomiting, be sure to offer rehydrating drinks like Pedialyte or Gatorade, and small portions of bland foods like rice, noodles, or toast. Call the pediatrician immediately if there is blood or bile in the vomit, or blood in the diarrhea.

• Your child has a high fever, or a recurring fever. A high fever means:
  • For babies 3 months or younger, 100.4ºF or higher
  • For babies 3 to 6 months, 101.1ºF or higher
  • For children older than 6 months, 103ºF or higher

• Your child is excessively sleepy, lethargic or cranky

If your child exhibits flu symptoms, call the doctor as early as possible; antiviral medication may help if it is given within the first 48 hours of flu signs.