Like an artist working with a wide brush, a window cleaner creates a soapy pattern before rubbing and scrubbing to make a storefront sparkle on Broome Street in Manhattan, January 26, 2006.

While street-level windows are easy to reach, New York's many skyscrapers present dangers and require tapered ladders, cherry pickers, special belts or scaffolding platforms.

Glass buildings must be washed about twice a year, and windows on towering buildings more than 50 stories above the ground are far too dangerous for the casual cleaner.

"Before stepping onto any scaffolding, potential window washers must be trained," The Times wrote in 2017. "Members of the Service Employees International Union 32BJ, which represents property services workers, have to train for 216 hours in a classroom and another 3,000 hours hands on. That includes learning how to handle risks like the malfunctioning of equipment and problems with the weather."

Though height can add to the job's danger of the job, an invisible force is the main concern: the wind. "The wind - whether you're working scaffold, on belt or on ladder - is very dangerous," said a veteran window cleaner. "It's a nonstop checkpoint. You're checking every 15 to 20 minutes to make sure that everything is O.K. If for any reason I get disconnected from the building, the wind is gonna flip me over."