MESA, AZ - It's a virus that can affect your child and in severe cases can send them to the emergency room.
Doctors at Cardon Children's Medical Center say RSV cases could get worse as the fall season begins.
RSV, or Respiratory Syncytial Virus, infects the lungs and causes cold like symptoms in many sufferers.
In children or people with compromised immune systems, the virus can cause much more serious problems.
The lung infection can lead to difficulty breathing, wheezing, high fever, severe cough and the skin may appear blue from a lack of oxygen.
The virus normally rears its head in the fall but doctors tell ABC15 they've seen severe cases throughout the summer which concerns them as flu season begins.
Other conditions like the flu or asthma for example, can make the problem worse.
The virus affects children, the elderly and people with weakened immune symptoms, but most only experience mild cold-like symptoms.
If you or your child experience the severe symptoms, you should seek medical attention