Donald Plaisance Jr. likes to be prepared.

That’s why the St. Tammany Parish Sheriff’s Office deputy first class keeps a box of medical gloves in the door of his vehicle, so that when he gets a call for a medical emergency, he can don the gloves on his way to the scene.

That preparedness served him well Saturday night when he and Deputy Bryce Morse — a new recruit in his first week on the job — were called to a medical emergency just north of Interstate 12.

The pair weren’t told much, just that the emergency concerned a woman and a child.

When they arrived, the pair found a group of people gathered outside, Plaisance said Monday. One of them gestured toward a small car parked nearby.

“She’s in there,” the person said.

Plaisance walked over to the car, and despite his preparation, what he saw still took him by surprise.

“I had to step back for a second,” he said.

On the car’s front passenger seat was a woman with her foot propped up on the dashboard. She was in the midst of giving birth — Plaisance could see the baby’s head on the seat between her legs. He could also see that the baby wasn’t making any noise.

Plaisance immediately told Morse to get a flashlight and to radio EMS.

Complicating the situation was a language barrier. The woman spoke no English, so after getting someone from the nearby group to translate, Plaisance took the baby’s head and lifted it to clear the airway. When he did, he noticed that the umbilical cord appeared to be wrapped around the baby’s neck.

Using two fingers, he unwrapped the cord, after which the rest of the baby was born, sliding into his hands “like catching a football,” Plaisance said.

What’s more, as soon as the umbilical cord was unwrapped, the baby boy began crying, a sound that filled Plaisance, the father of a 6-year-old son, with relief.

Through the translator, Plaisance told the mother that she had given birth to a baby boy. She “smiled and nodded,” he said.

Through a hospital spokeswoman, the mother refused to be interviewed for this story.

But even though the baby was out, the umbilical cord was still attached, Plaisance said. Firefighters from Fire District 12 had arrived, and they put blankets around the baby and clamped the cord in preparation for its being cut, he said. Emergency medical technicians also had arrived, and they cut the cord before putting mother and baby into an ambulance for transport to Lakeview Regional Medical Center.

“It was an adrenaline rush for sure,” Plaisance said of the encounter. But it wasn’t the first time he has been involved in a similar situation.

On Christmas morning in 2011, Plaisance responded to a medical emergency and found a man who had no vital signs. Plaisance performed CPR on the man, reviving him and earning a Life Saving Award from Sheriff Jack Strain.

Strain praised Plaisance again Monday.

“It is not very often that one of us is blessed with the opportunity to bring new life into the world,” Strain said, adding he was proud of the way Plaisance handled the situation.

Plaisance went to the hospital Sunday and was able to visit with the woman and see the child, both of whom are healthy, he said. The boy came in at a solid 6 pounds, 12 ounces, he said.

Plaisance also had to endure the gentle ribbing of some of his colleagues, who asked if he wanted to pick up some shifts at the hospital’s maternity ward.

“I don’t want to go through it again,” he said. “But I am glad I went through it.”

Follow Faimon A. Roberts III on Twitter, @faimon.