When New York City was hit with a snow squall a few weeks ago, Albert Hei, 29, took refuge in an igloo.

Well, a fake one, with modern accouterments.

The plastic dome had been installed on the roof of the Time Out Market New York in Dumbo, Brooklyn. It can comfortably fit eight people and is decorated with twinkle lights and fur throws. Mr. Hei sipped a hot toddy with his mother and the snow swirled around them.

“We were engulfed in this cloud,” he said. “It was like a winter wonderland. It was the last place I thought I would find myself.”

Not everyone will be lucky enough to have a snow squall, but rooftop plastic domes are everywhere this winter. Over a dozen hotels, bars and restaurants are putting up prefab snow globe-type structures in their outdoor spaces. There are now places in the city where you can sit in one rooftop fake igloo and watch people hanging out in other fake igloos below. Competition for the plastic dome drinker is becoming intense.

According to Sal Rozenberg, the director of operations for 230 Fifth Rooftop Bar near the Empire State Building, the fake igloo wars have hit. His lounge, where rooftop drinkers are lent fluffy red robes, first offered plastic domes in 2015. Now he gets two or three emails a week from other bar owners about where to get their own fake igloos. He’s not always forthcoming in his responses.

“I find out where the people emailing are located,” he said. “If they are in a different city or state I give them contacts and links and all that. If they are from New York City, I tell them about the company that built our original ones, not our current ones that are metal and so much better,” he continued. “I want to have the better product.”

Most New York bars seem to be using the same type of structure: plastic sheeting, zippered door, accommodates eight. It can be ordered online and costs as little as $800. While the domes look simple, installing them, which requires hours of manual labor involving about 400 pieces, is tough, said Mark Briskin, the general manager of the Park Terrace Hotel, which has two fake igloos on its roof.

What sets the structures apart are their locations and the views that come with them. City Winery operates four of them in Rockefeller Center.

“You are enclosed in this little bubble,” said Hannah Jentz, 28, who recently spent an evening during the holidays there. “You can see the tree, you can people-watch, but you get to escape from the cold, and you don’t have people bumping into you.” In the first two weeks of the month, City Winery had more than 1,000 reservations for the domes.

Starting in mid-January, Hyatt Centric Times Square will have fake igloos on the 54th floor, where views extend from the East to the Hudson Rivers, and in just a few days, the TWA Hotel at Kennedy International Airport will open a chalet for its local activity of plane spotting.

Farther out on Long Island, Gurney’s Resort in Montauk has installed them near the beach. Ms. Jentz is planning a visit. “You get to look at the ocean even though it’s cold out,” she said.

Some venues have started to expand beyond the simple plastic tents, introducing entire pop-up winter palaces with furniture, greenery and lights, like the courtyard yurts at the Hoxton in Williamsburg.

There is also a temporary chalet on the roof terrace of Mr. Purple, on the Lower East Side, which has a chandelier made of antlers, a Champagne bar, and 360-degree views of the city. The Ophelia, not far from United Nations, covered its outdoor bar to look like a snow globe. And the Arlo SoHo has gone all out, building two winter cabins made of cedar, surrounded by faux white birch trees.

But as the fake igloo concept expands, the novelty also starts to wear off. Mr. Hei, who was lucky enough to witness the snow squall from inside one, knows what’s coming.

“When things get too trendy they start to get less fun,” Mr. Hei said. “Also you know how social media is these days. Once everyone wants to try it, you will have to wait a crazy amount of time.”

Mr. Rozenberg, of 230 Fifth, is already thinking about what is next. “We were thinking of putting in a ski lift, a little ride across the roof,” he said. “But the engineering is out of control.”