Temperatures are expected to be well below normal for the next three days, with Wednesday's high only reaching 30, with wind chills of about 20.
Forecasters say more snow, sleet and freezing rain are possible Saturday and Sunday.
The freezing cold turned the precipitation that fell Tuesday into ice. Driving can be especially slick on elevated surfaces and on ramps leading to and from highways.
Boris from Staten Island returned to his car in Downtown Brooklyn Tuesday night to find water droplets on his windows were frozen solid.
"That's the danger, because it's frozen. You will not see it on the road, you will not see it on your windshield," Boris said, "Many things are dangerous, some things you can prevent."
Sanitation crews are working around the clock to salt down trouble spots like in Park Slope.
With the mercury dropping, the city's Office of Emergency Management is monitoring every step of the coming deep freeze.
It could also have an impact on mass transit too.
And then there are the sidewalks, many of which in the neighborhood never were properly shoveled before the temperatures took their tumble.
"You have to be careful when you walk because you're going to slip and, you know, get hurt," said Victor Soto, a pedestrian.
"That's why I got my arm around her, in case she falls, she falls backwards with me," said Kenny Mohabeer, a pedestrian.
Information about storm responses can be obtained on the city's website or by calling 311.
New Yorkers are also encouraged to sign up for the Notify NYC system. It sends information through phone calls, text messages and email alerts.
CLICK HERE to download the AccuTrack Weather Alert App.