Based on a new study published in their Morbidity and Mortality Weekly Report, the CDC has some suggestions that can reduce potential exposure to COVID aerosols by up to 95 percent. According to the health authority, you can either “double mask” by layering a cloth mask over a surgical mask, or add something else on top of your mask to enforce the outer seal and prevent air leakage or gaps, like a mask fitter or a sleeve made of sheer nylon hosiery. “We know that universal masking works,” John T. Brooks, MD, medical officer for the CDC’s COVID-19 response, recently told The Washington Post. “And now these variants are circulating… whatever we can do to improve the fit of a mask to make it work better, the faster we can end this pandemic.” While the CDC says that there are still some circumstances in which a simple cloth covering or medical mask will continue to be sufficient, they gave four examples of destinations that warrant a mask upgrade. Read on to learn where a better mask is a must, and to find out which masks to avoid, check out The CDC Warns Against Using These 6 Face Masks. While the CDC acknowledges that your regular mask might be fine for “talking with neighbors when you are outdoors and are at least six feet away,” a trip to the grocery store is a different story. There, you’re likely to contend with narrow aisles that complicate social distancing, as well as questionable ventilation systems.ae0fcc31ae342fd3a1346ebb1f342fcb In fact, some experts say that you should only go inside the grocery store as a last resort during this heightened-risk stage of the pandemic. “Shopping for five minutes in the grocery store is a lot better—six times better—than shopping for 30 minutes,” Tom Frieden, the former director of the CDC, recently told Vox. “Picking up groceries at the curbside is even better, and having them delivered is even better still,” he added. And for more on places to avoid at the moment, find out Where You’re Most Likely to Catch COVID Now, New Study Says. While experts say it’s important not to skip necessary medical appointments out of fear of contracting COVID, this is one place where you definitely want to bring your best masking system. Trips to the doctor’s office typically include time spent with others in a waiting room, as well as close contact with medical staff in a smaller exam room. Coming prepared with a well-fitting, highly protective mask is essential for keeping both you and medical personnel safe. And for more on masks that won’t fit the bill, check out The One Face Mask That’s “Unacceptable,” According to the Mayo Clinic. The CDC says that if you’ve been “working at a job where you are exposed to people who do not live with you and you are not always able to maintain at least six feet of distance from others,” it’s wise to wear an upgraded mask. While errands and other outings might put you at risk for a shorter period of time, most people working on-site will be at heightened risk for many hours of the day. Minimize your chances of infection by layering your masks or adding features that improve fit. And for more COVID updates sent right to your inbox, sign up for our daily newsletter. While open-air travel such as walking or biking may be a COVID-friendly solution to your commute, there are times when riding on public transit may be necessary, especially during these colder winter months. As the CDC now recommends, you should plan on wearing a better-than-average mask “any time you are traveling on a plane, bus, train, or other form of public transportation traveling into, within, or out of the United States and in U.S. transportation hubs such as airports and stations.” And if you’re anxious about when you’ll be able to get vaccinated, know that Dr. Fauci Says You’ll Easily Get a Vaccine Appointment After This Date.