California’s children’s hospitals have been struggling lately to provide care for a steady stream of young patients suffering from respiratory illnesses.

Children’s Hospital Orange County has been seeing a massive increase in patients lately, prompting longer than usual wait times in the emergency room.

The hospital has been dealing with around 450 patients per day, many with suspected cases of RSV, up from its typical case load of about 200 to 250, according to the Los Angeles Times.

On Nov. 1, a health emergency was declared in Orange County due to rapidly spreading virus infections.

The spread has health officials concerned about patients’ well-being, especially in the younger children.

“In infants, especially under age one and those with underlying heart and lung disease, it can go down into the lungs and cause inflammation and infection in the tiny airways. We call this bronchiolitis and it can really cause severe breathing issues and hospitalizations, often for young infants,” pediatrician and author Dr. Tanya Altman said.

RSV can appear to be similar to the common cold, but is often much more serious.

CHOC provided a guide for parents on its website about when and how to prepare for a trip to the emergency room during this busy season.

At Children’s Hospital Los Angeles, a spokesperson told KTLA on Tuesday that they are finally seeing a slight decline in RSV cases, however, patients testing positive for influenza have been on the rise.