Cases of respiratory syncytial virus, a common and contagious illness usually seen in young children, has reached its peak at Oishei Children's Hospital in Buffalo.

The hospital reports it has treated a lot of cases of RSV so far this season. 

It's a virus that starts as a cold with a runny nose and low-grade fever that later moves into the chest, making it tougher for kids to breath. 

"Count how many breaths they take in a minute. Kids over time will get tired. Their muscles get tired. And that's when RSV gets dangerous. And so when you see your child working hard to breathe, you want to get a doctor to evaluate them,” said Jamie Wooldridge, Oishei Children's Hospital chief of pediatric pulmonary medicine.

While most kids can be treated with oxygen and fluids, RSV can be life-threatening for others with heart or lung disease or immune problems.

“Unfortunately, there's no medicine that fixes RSV. You have to wait, just like the common cold, until the symptoms resolve and it usually resolves itself in anywhere from seven to 10 days,” said Wooldridge.

RSV season is expected to diminish in early March.