The New York Police Department says the man called 911 from his cell phone Sunday afternoon and said his kayak was quickly taking on water in the ocean about a mile from Jacob Riis Park on the Rockaway Peninsula.
The man told police he was a fisherman.
An NYPD helicopter found the man in the water struggling to keep his grip on the overturned boat, which was almost completely submerged.
The man was lifted by rescue basket into the helicopter and taken to New York Community Hospital.
Police say he was suffering from severe hypothermia but is in stable condition. The man's name was not released.