A chum passed this onto me....
Program this number into your cell phone: 212-533-5151.
That's the number for the Bowery Residents' Committee (BRC) 24-hour homeless helpline. They have the city contract for picking up folks on the street when it's too cold to sleep outdoors. If you're out in Manhattan in the coming months and see someone who looks like they could use a warm bed, call the BRC. They'll ask you where you saw the person and what they're wearing, and then send out a van to talk with them.
Everyone involved will feel better.