Respiratory illnesses like COVID, RSV, and the flu are pushing U.S. hospitals to the brink this fall, U.S. Surgeon General Vivek Murthy said this week, as he urged Americans to take precautions against all viruses.

“Hospitals are filling up, children’s hospitals in particular,” he told ABC’s Good Morning America.

This fall, pediatric hospitals are brimming with an unusually high number of patients who are sick from several different viruses—predominantly RSV, flu, and COVID, but also influenza-like viruses like rhinovirus and enterovirus. As a result of this “tripledemic,” many hospitals are at or near capacity. Some are far beyond it, having made room for patient overflow in offices, gift shops, play areas, and parking-lot tents.

But adult hospitals are also struggling owing to the surge in respiratory illnesses. Federal health officials stand ready to deploy troops and FEMA personnel, and supplies like ventilators from the Strategic National Stockpile, they said in November, as they announced that the U.S. had officially reached epidemic levels of the flu.

Handwashing, masking in crowded places, staying home when sick, and getting the COVID and flu vaccine are simple steps Americans can take to free up hospital beds for those who truly need them, Murthy said.

“It’s more important than ever … that we take these measures, because they’re one way that we can take care of our kids, [and] also relieve the strain on health care workers.”

The federal government is supporting hospitals in need with “personnel, ventilators, equipment,” Murthy said. “We are also working closely with them to coordinate so that across a given region or a state, beds can be utilized at the most efficient.”

U.S. COVID hospitalizations are again on the rise after a period of relative stability this fall. The seven-day average was nearing 5,000 last week after hovering for months in the low 3,000s, according to data from the U.S. Centers for Disease Control and Prevention.

Nearly 80% of all U.S. ICU beds are occupied this week, according to the Johns Hopkins University of Medicine Coronavirus Resource Center. The vast majority—nearly 56,000—are taken by patients who don’t have COVID, and just over 4,000 beds are taken by patients who do.

U.S. flu hospitalizations last week nearly doubled from the week prior, according to the CDC. They were higher than they had been during the same week every year since 2010, the agency said. Nearly 9 million cases of flu have been recorded this season, with nearly 80,000 hospitalizations and 4,500 deaths.

COVID-wise, at least, the country is in a better position this year to handle a winter surge, compared with the past two years, because of population immunity from prior infection and vaccination, in addition to antivirals like Paxlovid that can keep high-risk COVID patients out of the hospital, Murthy said.

“But we need people to use these tools,” he added, urging Americans to get the new Omicron booster if it’s been two months or longer since their last COVID jab.