As temperatures in New York City dip from cold to bone-chilling, Christmas tree vendors have bundled up and hunkered down in the safety of their vans and temporary shacks.

But on the southwest corner of 57th Street and First Avenue, Gilles Berube, a vendor from Quebec, works only in jeans, a scarf, a knit jacket and a hat. He does not hide from the cold, but wards it off with shots of vodka and rum.

“I was born in a snowstorm,” he says, by way of explanation.

Last Friday, in the kind of cold that numbs the toes, the presence of liquor attracted a few customers who stopped to have a drink with him, clinking little snifters of brown and clear alcohol. In a city where the business of selling Christmas trees can become contentious, and occasionally litigious, Mr. Berube is a welcome sight for many in this Manhattan neighborhood, where he has peddled trees for nearly two decades.

Because permits are not required to sell Christmas trees in New York, the city does not keep a tally of how many vendors set up shop here each year or how many trees are sold, but the number of trees collected after each season might be some indication. The city’s Sanitation Department estimates it collected 214,000 trees from curbsides last year, in addition to some 30,000 taken to mulch events hosted by the parks department.