New York City is experiencing a triple wave of respiratory viruses, and on Friday, city health officials warned residents to take extra precautions.

COVID-19 and influenza cases are all spiking simultaneously, while respiratory syncytial virus (RSV) infections are showing signs of improvement but remain high. The city said the resulting hospitalizations could overburden the local health care system.

Friday’s health advisory urged New Yorkers to mask up indoors and in crowded spaces, particularly if they’re at risk for severe illness (or know someone who is). But the health department didn’t call for the reinstatement of any mask mandates, and city Health Commissioner Dr. Ashwin Vasan said that with proper precautions, there’s no need to skip holiday gatherings.

“Vaccination and boosters are critical but so are common sense precautions like masking when indoors or among crowds and staying home if you don’t feel well,” Vasan said in a written statement. “Also, get tested before getting together, and get treated quickly if you test positive. We want everyone to have a happy and – most of all – healthy holiday.”

The city health department is reporting more than 3,800 new COVID cases per day on average — a 50% increase in confirmed infections since Thanksgiving. Many cases are also likely going uncounted because people are using at-home tests. State health department data shows 1,595 people currently hospitalized with COVID-19 in New York City, double the number from mid-September.

Flu cases are also rising dramatically. The health department documented more than 11,000 confirmed infections the week of Thanksgiving, up from less than 5,500 the week before. Cases normally peak weeks or months later in the season, the data shows. The city is averaging about 1,100 daily emergency department visits due to flu-like illness, which is double the number from late October.

The agency is also still recording thousands of RSV cases each week, topping out at nearly 5,000 laboratory-confirmed infections the week of November 12th.

The “tripledemic” can be seen nationwide: According to data from the Centers for Disease Control and Prevention, cases of all three viruses are on the rise.

“As we are all aware, nationally, we are seeing elevated levels of respiratory viruses including RSV, flu and COVID-19. Especially for RSV and flu, these levels are higher than we generally see this time of year,” CDC Director Dr. Rochelle Walensky said Monday.

“Compared to the week prior, hospitalizations for flu continue to be the highest we have seen at this time of year in a decade, demonstrating the significantly earlier flu season we are experiencing,” she added.