Emergency signs & symptoms of the flu, H3N2 virus

If you come down with the flu and you're a healthy adult, the quickest way to get over it is to stay home, get plenty of rest, and drink lots of fluids.

But in some cases, the flu can develop into something much more serious. And you should get medical attention right away.

For kids, those warning signs include a high fever or a fever that just doesn't seem to go away, trouble breathing or fast breathing. Changes in skin color, if they have a bluish tone, get to the hospital.

And if they're having trouble drinking or keeping down fluids, seek help because that could lead to dehydration. Also changes in their behavior, if they're not waking up or being so irritable that they don't want to be held, it's time to get to the doctor.

Dr. Melissa Denham with Patient First says, "One thing you want to look out for is if they start to get better the fever goes away and then they suddenly get worse again, high fever, worsening cough, short of breath, that could be a sign that it's turning into a bacterial infection like pneumonia which is one of the most common complications of the flu."

For adults and the elderly, if you have a hard time breathing, pain or pressure in the chest, you feel confused or like you're going to faint, seek medical attention right away.