Stores like Walmart are changing Black Friday shopping to make it safer. Experts say none of it will matter if shoppers don't wear masks.

• Several stores have added additional safety precautions ahead of the Black Friday shopping frenzy to protect both customers and employees.
• We spoke to three experts to find out which precautions will actually help.
• The experts agree that enforcing mask-wearing and social distancing are good, but mandates like reducing store hours may be unhelpful or detrimental.

Several big-name retail stores have added additional in-store safety precautions ahead of the Black Friday shopping frenzy, and we spoke to three experts to find out which precautions will actually help the most.

Major stores across the country have implemented a variety of safety mandates to keep shoppers and employees safe on the historically frenzied Black Friday shopping day as coronavirus cases continue to surge in the US. For example, some stores — including JCPenney and Lowe's— are offering contactless curbside pick-up, and others — such as Home Depot and T.J. Maxx — are requiring face masks.

The three experts we spoke to all agree that contactless curbside pickup and mandating face mask-wearing — retail protocols that have become normalized since the beginning of the pandemic — are beneficial to help stop the spread of COVID-19.

"We have data that show that large congregations of people, especially indoors, will lead to an outbreak," Dr. Jill Weatherhead, an assistant professor at Baylor College of Medicine, told Business Insider in an interview. "These other strategies [besides mask wearing] are really coming off of the knowledge that if we reduce people being in close contact by doing these other extra steps, hopefully, we can reduce transmission if people choose to go into stores."

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Stephen Kissler, an infectious disease researcher at Harvard's School of Public Health, thinks the most important action stores can do is limit the number of customers inside — a mandate Walmart recently reinstated — to decrease the chances of a superspreader event. Weatherhead notes that setting a cap on the number of in-store customers will be helpful as long as it doesn't create crowds of people waiting in close contact outside the store.

Mitigating the possibility of overcrowded stores

Stores like Michaels and Nordstrom will also be limiting store hours. However, Dr. Stanley Perlman, a professor at the University of Iowa's Carver College of Medicine, states this "may not be helpful if other rules are followed."

Both Kissler and Weatherhead take this a step further by expressing their concern over the strategy, stating that it may instead "backfire," according to Kissler.

"If you have more limited store hours, will it then lead to more crowded stores when stores are open?" Weatherhead said. "It doesn't seem like there would be a benefit to limiting store hours in terms of reducing viral transmission."

Weatherhead and Kissler suggest that stores should instead take the opposite approach: expand store hours to prevent potential overcrowding during the reduced hours.

Retailers like Walmart and Dick's Sporting Goods are also preventing the possibility of large crowds by spreading sales across multiple days, or creating digital queues so customers can wait remotely to enter the store, the latter an approach Target and Best Buy are taking. Both Weatherhead and Perlman agree that these tactics would work to lessen risk for shoppers.

Read more: Retailers are struggling to attract seasonal workers for what experts anticipate will be a 'tough holiday season'

Weatherhead and Kissler agree that reminders of social distancing in the form of markers or stickers on the floor are also helpful, although Perlman notes that they may not "help much."

"I think most people are starting to get used to this new normal of having to space out and having these visual cues available, so having the stores provide that it probably is not necessary, but it's a reminder to individuals to keep that distance when they can," Weatherhead said.

Some retailers like Lowe's are taking the social distancing reminders a step further by implementing "ambassadors" at the front of the store to direct customers or remind people to wear masks and social distance. According to Weatherhead, like the markers and stickers, these "ambassadors" help provide an additional "visual and verbal cue," although these workers should also be wearing PPE and socially distancing themselves.

Sanitizing and "wellness checks"

While offering hand sanitizer wipes throughout stores is helpful, and associates handing out sanitized shopping carts "may help a little," cleaning high-touch areas may be "less important than we thought at the beginning of the pandemic," according to Perlman.

On the other hand, offering hand sanitizer is a "low-cost, low-time activity that doesn't affect the shopper," according to Weatherhead, but enforcing social distancing and mask-wearing is more important.

Stores like Best Buy have also started implementing daily "wellness checks" for its employees. Perlman argues, however, that providing testing and PPE would be more beneficial. And according to Weatherhead, "data suggests that we likely don't identify as many people with the virus using daily wellness checks."

However, implementing these daily checks is important as it encourages employees to stay home with the support of their employers when they're feeling unwell, according to Weatherhead.