The U.S. Centers for Disease Control and Prevention has some advice for older Americans who are at a higher risk of getting "very sick" from coronavirus: "Stock up on supplies" and consider taking steps to avoid crowds. Here is a rundown of the latest guidance and a look at who is most at risk.

Who is at "higher risk" from coronavirus?

The CDC defines "higher risk" people as older adults and those with serious chronic medical conditions such as heart disease, diabetes or lung disease.

Dr. Nancy Messonnier, the director of the CDC's National Center for Immunization and Respiratory Diseases, emphasized during a telebriefing Monday that the risk increases as a person gets older.

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"I really think it's important for the American public to understand the risk," Messonnier said. "We use these broad categories of over 60 or over 65, but the data really says that as you get older the risk goes up."

She said the most serious risk of illness and death from coronavirus is in people over 80, especially if they have underlying health conditions.

Stock up on your medicines

On the CDC's website, health officials advised those at a higher risk of becoming very sick from coronavirus to make sure they have a supply of their regular medications on hand, just in case there's an outbreak in their community and they need to stay home for a prolonged period of time. Inquire about obtaining extra medications from your health care provider or use a mail-order service for medications.

The agency also reminded Americans to make sure they have enough over-the-counter medicines, like something to relieve a fever, plus medical supplies and household items such as tissues.

Older adults & people with severe chronic medical conditions like heart, lung, or kidney disease seem to be at higher risk for more serious COVID-19 illness. https://t.co/SlDrVXXfCz pic.twitter.com/MRCCeMuVrq — CDC (@CDCgov) March 7, 2020

Stock up on groceries

Don't forget about food supplies. "Have enough household items and groceries on hand so that you will be prepared to stay at home for a period of time," the CDC says.

Think about ways of getting food and other essentials brought to your home if you can't go out and do a shopping trip yourself. Are there family members, friends or coworkers, community organizations or local businesses you could call on?

Sanitary steps

In addition to stocking up on supplies, the CDC advised those at a higher risk to take "everyday precautions" like avoiding close contact with sick individuals. Wash your hands often (for at least 20 seconds at a time) or if soap and water isn't available, use a hand sanitizer that contains at least 60% alcohol, and avoiding touching your face.

"To the extent possible, avoid touching high-touch surfaces in public places — elevator buttons, door handles, handrails, handshaking with people, etc. Use a tissue or your sleeve to cover your hand or finger if you must touch something," the CDC recommends.

Stay home and practice "social distancing"

If the virus is already spreading in your community, the CDC advised older and high-risk people to stay at home "as much as possible." Stay away from crowded places, especially "closed-in settings with little air circulation" where germs can spread. CBS News chief medical correspondent Dr. Jon LaPook says practicing "social distancing" can really help.

"What I'm telling my patients is, you should use your common sense. You can't obviously hermetically seal yourself, but I would stay away from large crowds," LaPook said on "CBS This Morning." "If I had someone who was immunocompromised, this is not the time to go to the theater. This is not the time to do things where you could possibly be exposed." And he added, "This is certainly not the time to go on a cruise ship."

Know the symptoms

If you feel like you're developing symptoms including, fever, cough, and shortness of breath, call your doctor. Those could be signs of COVID-19, the illness caused by the coronavirus.

"If you develop emergency warning signs for COVID-19 get medical attention immediately," the CDC says. Those warning signs may include difficulty breathing or shortness of breath, persistent pain or pressure in the chest, a new onset of confusion or inability to arouse, bluish color to the lips or face, or possibly other issues that require immediate medical care.

Higher-risk people "should be taking extra precautions"

On "Face The Nation" Sunday, U.S. Surgeon General Dr. Jerome Adams said the latest data from China shows the average age of people who have died from the novel coronavirus is over 80. The average age of those needing medical care for it is over 60.

"And so what we're telling folks is that if you're in an at-risk group — meaning you're elderly and or you have comorbidities: heart disease, lung disease, you're immunosuppressed for whatever reason — that you should be taking extra precautions not to put yourself in a situation where you may be exposed," Adams said.

The guidance comes as the number of confirmed cases of coronavirus in the U.S. has risen to over 500.

The illness is blamed for at least 24 deaths in the U.S. as of Monday — a fraction of the more than 3,800 deaths worldwide, according to data compiled by Johns Hopkins University. More than 110,000 people have caught the virus globally, but the Johns Hopkins data show that almost half — more than 62,000 — have recovered.

The health risks associated with the virus rise significantly with age, and many younger, otherwise healthy people who contract it show only mild symptoms or no symptoms at all.

Messonier said that based on information from China, where the outbreak began, about 80% of patients had mild cases and recovered, while 15% to 20% developed more serious illness. Only about 2% of cases affected children.