Part of a series of stories on experiences that the pandemic has curtailed — and whether they’re worth saving.

Natalie Pariano was feeling some pandemic-related wanderlust and found herself looking through old travel photos when something stopped her scrolling finger dead in its tracks.

It was a shot of her head poking out of a pool of pastel-colored balls.

The picture was from a 2019 trip to the Color Factory, an immersive, Instagrammable attraction in New York City that features rooms full of colorful installations.

At the time, it had felt perfectly natural to dive in. But now?

“I just stopped at that photo and thought, ‘Oh, I’ll never get in a ball pit again,’ ” she says.

What once looked like an ocean of color is now a sea of respiratory droplets. Unsafe waters. A breeding ground for extremophile bacteria, like the darkest crevices of the Mariana Trench.

When it comes to the risk of coronavirus infection, “we talk about the three C’s,” says Peter Raynor, a professor at the University of Minnesota School of Public Health. “Closed spaces, crowded places, close contact.” Ball pits have all three.

Are they essential? Hardly. That’s kind of what makes them fun. But needless to say, the majority of ball pits in the United States are closed right now, and nobody’s in a huge hurry to reopen them. They’re listed in Phase 4 for Massachusetts, and they weren’t included in the recreational facilities permitted to reopen in California. Tennessee reopening guidelines call ball pits “areas where social distancing is difficult or impossible to maintain” and require they be off limits to visitors.

That has been catastrophic for the ball-pit industry, says Jim Sitton, president of 21st Century Products, which manufactures ball-pit balls.

“Covid has pretty much shut our business down for the moment,” Sitton says. “If the industry comes back, hopefully we’ll be around to see that happen.”

McDonald’s has closed its PlayPlaces. Ikea’s children’s play area, Smaland, “will remain closed at this time as an added safety measure,” says an Ikea spokeswoman. “We are unable to comment about the future of ball pits at this time.”

At the Lane, a family social club in D.C.’s Ivy City neighborhood, founders Molly Nizhnikov and Rachel Lubin packed up the balls from their ball pit earlier this month. Their business is open for private events and summer camps. “We’re not going to address the idea of whether or not there will be a ball pit when we come back until we know what the rest of the world will look like,” Lubin says.

It’s not just kids who are going without. Among adults, ball pits have undergone a resurgence as millennials’ nostalgia and fondness for Instagram have found them flocking to highly stylized photo traps, such as the Color Factory or the Museum of Ice Cream. There’s always a ball pit, or some variation (a pool of plastic sprinkles at the Museum of Ice Cream, a vat of foam marshmallows at Candytopia) — irresistible to ’90s babies who spent childhood birthday parties luxuriating in the ball pits at Chuck E. Cheese or Discovery Zone. In 2015, the National Building Museum’s immersive indoor summer exhibition, “The Beach,” included a monochromatic ball pit that evoked a gigantic bubble bath. Families and young adults alike swarmed the exhibition and broke the museum’s visitor record.

“They bring out this joyful childishness,” says Beth Wolfe, a yoga instructor who taught classes at the Building Museum. “I would see women holding hands like, ‘One, two, three, jump!’ like you would at a pool party when you were 10.” (Would she go in one now? “It’s unthinkable.”)

Those days are now disappearing over the horizon of our new germaphobic era. The overseers of ball pits have been thinking about what it would take to make people feel safe wading back in.

A publicist for the Museum of Ice Cream shared diagrams for a new version of the sprinkle pool, revamped for the coronavirus age: Instead of a slide dumping germ-carrying guests directly into the sprinkles, the museum is going to build small, easily cleanable islands in the middle, so people can get in the pool without touching the sprinkles.

The Color Factory washes its balls in a ball-pit washing machine (yes, those exist) and when it reopens, there will be additional safety factors. The exhibit will limit capacity and require masks and sanitizing before and after people enter the pit. Cleaning normally would happen behind the scenes, but the factory will make the sanitizing process more visible to put people at ease. It will also use machines to deploy a disinfectant “fog” on the balls, similar to the kind that airlines use to sterilize airplane cabins. And its balls, which are purchased from Sitton’s company, contain an antibacterial agent in the plastic. “I would contend that — in a pre-covid world, and especially in a post-covid world — that we have the cleanest ball pit on the planet,” says Jeff Lind, Color Factory’s chief executive.

But antibacterial is not anti­viral. And reassurances and frequent cleanings may not be enough. Raynor, the public health professor, says he thinks it would be pretty embarrassing for someone who contracts the corona­virus to have to admit to a contact tracer that they had been playing in a ball pit during a pandemic.

“It’s something that’s not necessary, and it’s kind of pointless,” he says. “Why take the risk at this point in time?”

What about at a later point in time? Will anyone see ball pits the same way? The thing to remember is that even before there was a wildly contagious virus stalking humanity, ball pits had a reputation for being rainbow-colored kiddie petri dishes of bacteria. Researchers from the University of North Georgia studied ball pits in physical therapy clinics a few years ago and found “considerable microbial colonization, . . . including 8 opportunistic pathogenic bacteria and 1 opportunistic pathogenic yeast.” (That’s bad.) McDonald’s ball pits have a reputation for churning up gross little discoveries, such as used bandages and dirty diapers. The Building Museum’s “Beach” swallowed people’s shoes, wallets, sunglasses and cash, and for a few people, it was an unfortunate source of conjunctivitis, or pinkeye. There’s a running joke on social media that the novel coronavirus originated not from a bat, but in the depths of a Chuck E. Cheese ball pit.

Ball pits are frivolous, but fun is essential. And for kids, someday, there will be an opportunity to dive back in — whether it’s at home (you can buy a personal $231 faux-marble velvet mini-ball pit, the perfect aesthetic for an aspiring child influencer) or, eventually, in a safe public environment. But for adult children, perhaps they’re a little overplayed. Every Instagram museum has a ball pit now, and everyone’s ball-pit selfie looks the same. They’ve become a visual cliche.

“I think we’ll survive as a civilization without ball pits,” Raynor says.

As for the Instagram influencers who popularized ball pits, they might move on to more hygienic ways to recapture their youths. Christine Tran Ferguson, 34, has more than 300,000 followers on her fashion and travel Instagram, and she says she won’t be visiting any ball pits when they reopen.

She thinks a beautifully designed swing would be a good replacement: great for pretty Instagram poses, and “you can just wipe it down and sanitize it easily.”