Cases of COVID-19 have surpassed 100,000 worldwide and spread to 100 countries, according to the World Health Organization (WHO). While the outbreak seems to be slowing down in China, where it originated in December, other countries are reporting large jumps in confirmed cases and the global death toll continues to rise.

Most people who become infected with COVID-19 will experience mild symptoms and recover on their own without being hospitalized. However, for those who are over the age of 60 or have underlying health conditions, the virus can cause serious health complications and even death.

Of the 19 deaths in the U.S., at least 14 people were over the age of 60, and in Washington, about half of the 136 confirmed cases involved people over 60. Just as the threat of the virus is known to increase with age, it’s also cause for concern among people with health conditions, such as heart disease, lung disease, kidney disease and diabetes, and those with weakened immune systems.

To help limit the possibility of exposure, on Friday, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told people who are most vulnerable to consider rethinking their travel plans. That includes getting on a plane, taking a cruise or even just going to a local venue that’s crowded, as large gatherings of people are known to foster the spread of infections.

“The general risk to the American public remains low,” Vice President Mike Pence said. “But if you are an individual with a serious underlying health condition or—and are elderly, it’s important to take precautions and use common sense, particularly as it relates to travel.”

Taking additional precautionary measures aren’t just designed for vulnerable populations, but also for people who interact with them, including mixed-generation households.

Ambassador-at-Large Dr. Deborah Birx told reporters on Friday that her household is home to her 91- and 96-year-old parents, as well as her grandchildren. In households similar to hers, she encouraged adults to ensure kids are practicing proper hand hygiene and that they’re separated from their grandparents if they become ill.

As tempting as it may be to wear a face mask, the Centers for Disease Control and Prevention (CDC) has not advised anyone other than those who are showing symptoms of COVID-19 or caring for someone with COVID-19 to wear one.

Thirty-four states have reported cases of COVID-19 and the CDC advised vulnerable people to stay home as much as possible if the virus was spreading in their community. To limit outside interactions, the CDC recommended people utilize their family members and social and commercial networks to arrange for food to be brought to their homes.

Those who live in parts of the country where an outbreak hasn’t occurred should prepare for the possibility it could happen. Preparations should include having enough groceries, household items and necessary prescription and over-the-counter medicines to remain at home for a prolonged period of time.

For months, WHO issued guidance for the general public to protect themselves against the virus. Officials encouraged people to wash their hands thoroughly, stay at least three feet from someone who appeared sick and avoid touching their faces, as it can transfer the virus from a surface to a person.

On Monday, Dr. Mike Ryan, executive director of the WHO Health Emergencies Programme, said it may be time to issue specific recommendations for high-risk groups.

“We will definitely take a strong look at that in the coming days,” Ryan said during a press briefing.