It's the calling card of one of the viruses making plenty of people miserable this winter.
RSV, or respiratory syncytial virus, can be dangerous, even potentially life-threatening for some kids, even though it is mild in most children and adults.
Many doctors' offices and hospitals are swamped with cases.
"At this point, almost the entire floor here is full with patients with RSV," says Dr. Sam Stubblefield, a pediatrician at Bryn Mawr Hospital.
And that's the way it's been for weeks.
Sometimes, 80% of the young patients have RSV.
Doors to patient rooms are closed, and anyone going in or out has to wear protective gowns and gloves. It's all to keep the highly contagious respiratory virus from spreading.
RSV hits children under the age of 2 the hardest, especially infants, premature babies, and kids with underlying ailments like asthma.
Dr. Stubblefield describes them," They have trouble with their breathing, so much congestion they can't deal with it. Frequently they end up with a really bad cough, and they throw up after they cough. Sometimes they have really low oxygen levels, and we have to give them extra oxygen."
For older and healthy kids, RSV looks more like the common cold. There is no real treatment. It just has to run it's course.
But for those at a greater risk, there are signs to watch out for.
"They're breathing more than 60 times a minute, or anytime their lips are blue, or they are blue in the face, that's an emergency and 9-1-1 should be called," says Dr. Stubblefield.
Adults also get RSV, but it's normally much milder. However, it can lead to that nagging cough you may be hearing from co-workers.
RSV can live on hands or hard surfaces for hours.
So wash your hands frequently, especially after having any contact with someone who seems to have a cold.
And keep school-age kids with a cold away from younger siblings, especially infants, until the cold is gone.
Parents can get much more information on RSV from KidsHealth.org.
