Millions of people are getting ready to gather with their family and friends for Thanksgiving, celebrating the holiday in a way that most closely resembles pre-pandemic ways for the first time in more than three years.

However, respiratory illness activity — defined as people going to the doctor with symptoms of any respiratory illness such as fever, cough or sore throat — is increasing across some areas of the United States, according to the latest data, updated Friday by the Centers for Disease Control and Prevention (CDC).

Additionally, emergency department visits due to flu, COVID and RSV are rising. Hospitalizations for flu and COVID are ticking up, but remain lower than the same time last year. RSV hospitalizations are increasing in areas tracking new admissions.

Experts said there are a few well-known mitigation measures you can follow to keep yourself and your loved ones safe during the holidays.

“There are safe and effective ways to prevent the bad outcomes of these diseases and it relies very much on the ABCs, staying up to date with vaccinations, testing yourself, staying home if you’re sick, contacting your primary health care provider if you test positive to know if you’re eligible for getting treatments, and then doing the everyday things to protect your loved ones,” Dr. Albert Ko, a professor of public health, epidemiology and medicine at Yale School of Public Health, told ABC News.

Exercise caution when traveling

While most people will be traveling by car, AAA projects 4.7 million travelers will fly over Thanksgiving, which would be the highest number since 2005.

There will also likely be millions of people traveling by train or by bus to holiday gatherings.

Although it is not required by any transportation companies, experts said people may consider wearing well-fitting masks, that cover their noses and mouths, if they are in crowded or poorly ventilated areas.

This is coupled with good hand hygiene, including washing hands with warm water and soap for at least 20 seconds, or using hand sanitizer when hand washing isn’t available.

However, the most important thing someone can do is stay home when sick, said Dr. Perry Halkitis, dean and professor of biostatistics and urban-global public health at Rutgers School of Public Health.

“The number one responsibility that we all have is that if we’re feeling ill or slightly feeling ill or even beginning to feel ill, that we question whether or not we should travel,” he told ABC News. “The number one thing that I would encourage people to do, if you’re feeling ill, if you are potentially infectious, try not to go into large crowds, into situations where you can infect people.”

Be up to date on vaccinations

Experts say one of the best ways that people can best protect themselves is to stay up to date on vaccinations.

For COVID-19, there is an updated vaccine formulated to target variants currently circulating that are related to XBB, an offshoot of the omicron variant, for those aged 6 months and older.

Halkitis said he often has conversations with people who ask why they should get the updated vaccine when they already got the primary series. He replies that it’s similar to the flu vaccine, which is updated every year to target circulation.

For the majority of those aged 6 months and older, the CDC recommends receiving the standard quadrivalent flu vaccine, which protects against four different strains of the virus. High doses are available for those aged 65 and older.

For adults over age 60, two vaccines are available. For babies under 8 months old, and some babies between 8 months and 24 months, there are two monoclonal antibody shots available. The right one depends on a child’s age and underlying health conditions. People can also get an RSV vaccine during pregnancy that protects their infant after birth.

“As we’re going into this winter season, we’re actually getting back to normal,” Ko said. “So, getting back to normal means that we’re going to be having, during the winter season, increases in many of the respiratory diseases that we had in the past, and we have ways to immunize people against many of these threats that we’re going to face in the winter.”

Consider taking a rapid test

Currently, rapid at-home tests are available for COVID-19. Tests for flu and RSV require visiting a health care provider.

Experts told ABC News that people should take a rapid test before attending a gathering if they are experiencing symptoms. If it’s positive, stay home and follow CDC isolation guidelines. If it’s negative, you should not necessarily assume you don’t have COVID and should consider taking another test 48 hours later.

Ko said that people can also consider taking a test if they will be gathering with people at high risk for severe complications from COVID-19, including those who are elderly, having underlying conditions or who are immunocompromised.

Open windows or doors for ventilation

Experts said that, if it’s possible and not too cold, to host Thanksgiving outdoors. If that’s not possible, they suggest opening windows and doors for ventilation.

The CDC says that improving ventilation can reduce virus particles in the home to keep respiratory diseases, such as COVID-19, from spreading.

“Ventilation is an important way that we can control infections,” Ko said. “Not all infectious diseases are the same. They’re not all transmitted in the same way … Ventilation is particularly important in those types of diseases where we have a lot of aerosol transmission and COVID is one good example.”

Another option is buying air filters, particularly high efficiency particulate (HEPA) air filters. HEPA filters can remove at least 99.97% of airborne particles, according to the Environmental Protection Agency.

Importance of staying vigilant

Halkitis said over the last year or so, he has seen, from many people, a tendency to want to go back to the way things were prior to COVID-19.

“That’s okay because there are vaccines available for several of these respiratory viruses,” he said. “The problem, of course, is that the uptake of [some of] these vaccines is dismal at best and, as a result, going back to normal, when you’ve added COVID-19 to the mix and RSV to the mix, above flu and the common cold, creates a condition where a lot more people are going to get sick.”

CDC data currently shows that hospital bed occupancy and capacity remain stable, but the more people that get sick and need medical care, the more a burden is placed on the health care system, Halkitis said. He said it’s important to stay vigilant when it comes to preventing the spread of illnesses.

“If you look at the numbers, all of the numbers are moving in the wrong direction. There’s increases in RSV, there’s increases in flu, there’s increases in COVID,” he said. “So, keep your eyes on what’s happening with the trends and make your decisions about where to go and what to do based on what you’re seeing. Let the science direct your behavior.”