An Irish-born FDNY medic heroically jumped into the freezing Hudson River on Saturday afternoon to save a suicidal man who had jumped into the water.

Paramedic Niall O’Shaughnessy, 40, a Long Island resident and a native of Co. Limerick, and his partner Mingze Wu were driving up the West Side Highway in Lower Manhattan at 2:50 pm  when they saw a gathering of police officers near the river’s edge at Harrison and West Sts, the NY Daily News reports.

An unstable patient had escaped a Lower Manhattan hospital and attempted to commit suicide by jumping into the Hudson.

“(The cops)had put down a life ring and was trying to pull him up but he was starting to slip off the life ring,” said O’Shaughnessy, an 11-year veteran of the New York Fire Department.

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Despite the temperature in the low 20s and falling snow on Saturday, the daring paramedic removed his equipment belt, grabbed a flotation device from his truck, and jumped into the arctic waters after the man.

“I swam behind him and locked my arms around him to keep him secure,” said O’Shaughnessy. “My partner and firefighters from Engine 10 began pulling us up.”

The cold quickly set in.

An unstable man who escaped from a New York hospital on Saturday and jumped into the Hudson River is rescued by FDNY paramedic Niall O'Shaughnessy and other first responders. Credit: NYPD SPECIAL OPS

An unstable man who escaped from a New York hospital on Saturday and jumped into the Hudson River is rescued by FDNY paramedic Niall O'Shaughnessy and other first responders. Credit: NYPD SPECIAL OPS

“Within about 30 seconds, I could definitely feel it in my arms and legs,” he said. “They weren’t really working. I couldn’t barely get my hand around the ladder they had sent down.”

The man he was rescuing was doing much worse.

“He was lethargic and definitely hypothermic,” O’Shaughnessy said. “He was having trouble forming words.”

NYPD and FDNY harbor boats arrived, and first responders were able to pull both men to safety.

It is not the first time the native Limerick paramedic has been dubbed a hero. In July 2015, he jumped into the Hudson River to save a woman from drowning.

O’Shaughnessy, then 38, dove into the grimy New York river on a Monday morning when he noted the woman was in dire distress.

The FDNY paramedic had told the New York Post: “This was my first time I jumped in the water [for a rescue].

“I have no idea why she jumped in, my concern was to just get her out.”

Aerial view of Lower Manhattan. Credit: iStock

Aerial view of Lower Manhattan. Credit: iStock

O’Shaughnessy has also put himself in danger for a stranger a third time. In July 2014, he was the heroic paramedic who jumped between subway cars to aid an Irish J-1 student who had fallen onto the tracks at the 49th Street station in Midtown.

J-1 student Mary Downey, from Belfast, had fallen from the platform and, while only suffering a broken shoulder, was stuck under the subway train.

O’Shaughnessy, along with firefighter Sean Cummins, a native of Dublin, were first responders.

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After his latest heroic rescue, O’Shaughnessy was taken to Lower Manhattan Hospital for a “warm up,” he said.

“I’m OK,” he added. “I’m doing good now.”

The man he rescued was taken to Bellevue Hospital, where he is listed in stable condition.

O’Shaughnessy’s EMS colleagues have called him a “true hero.”

“It takes courage to do what Niall did today, placing his life on the line to save others,” said Oren Barzilay, president of EMS Local 2507. “He's a true product of FDNY EMS, the best EMTs and paramedics.”