We get a call for an “unknown,” which means an unknown condition reported by an anonymous caller. The address is for an apartment building on Ocean Avenue, apartment 4D.

But when we get to the apartment on the fourth floor of an old walkup no one answers the door. Since the first thing a 911 operator asks is the caller’s phone number, we radio central dispatch to ask for a callback.

While that’s being done, the building’s super informs us that a 90-year-old man lives in the apartment, but no one’s seen him for days. The police arrive, to take down the door if necessary.

There’s no foul odor in the hallway, so I’m not too worried. We knock harder.

Finally, the latch turns, and an old man in a wheelchair opens the door. His unwashed clothes hang loosely off his shoulders and hips, and the sparsely decorated apartment reeks of urine.

“Sir?” I ask. “What’s the matter?”

He looks surprised. “Huh?”

“Are you okay?” I ask.

The apartment contains an old TV set, a chair, and a single bed. Six suit jackets hang inside an open closet. An open cardboard box on the floor spills out some floral-print blouses.

“I’m fine,” he says. “Legs is a little weak, though. Was hurtin’. Can’t seem to stand up on ’em.” He has the accent of a Southern gentleman.

One of the police officers says, “North Carolina?”

The old man replies, “Yes, sir.”

His legs are so swollen that my slightest touch pains him.

Dispatch radios us back and says the call came from the Veterans Affairs hospital. Mr. Robinson missed his dialysis appointment this morning. “Mr. Robinson,”I say. “What day is today?”

He thinks hard. “Wednesday.”

“It’s Tuesday,” I tell him. “What days do you go for dialysis?”

“Tuesdays and Fridays,” he says. Then it hits him, and his shoulders sag. “Oh poop.”

“The VA called us,” I say. “They were worried when you didn’t show up this morning.”

“My legs,” he says, rubbing the knees. “They was hurtin’ some.”

I can’t imagine those legs getting him to the hospital. “Who usually takes you there?”

“I take the bus,” he answers.

I can’t imagine him climbing down four flights of stairs and taking the bus. I don’t want to imagine the looks people give him when the foul odor of uric acid from his failing kidneys hits their noses. “We’ll take you,” I say, and begin my paperwork while my partner Bronson gets the stair-chair, an ambulance version of a wheelchair. “How old are you, Mr. Robinson?” I ask.

“Ninety-five,” he says.

Aside from his legs, he’s in remarkably good shape for a man his age. “When were you born?”

“May 15th, 1912.” I do the math on my fingers. “That makes you 92.”

He laughs. “I’ll take your word for it, you’re younger than I am.”

I say, “Yeah, but I have to count on my fingers.”

He shrugs. “Ain’t nothin’ wrong with that.”

The officer asks Mr. Robinson what war he fought in. “World War II,” Mr. Robinson says.

I call the VA directly. The dialysis nurse is glad to hear from me. “Are you bringing Mr. Robinson in?” she asks, anxiously. “When are you bringing him in?” Dialysis nurses see the same patients twice a week for years. They become attached.

I tell her he’s fine, we’re bringing him now.

She sighs in relief. “We were worried.”

“The VA gave me a birthday party, you know,” Mr. Robinson says, smiling. “Cake and everything.”

I ask him if there’s anyone we should call for him.

“My granddaughter,” he says, and tells me her number. There’s a photo on his bureau of a young girl in graduation cap and gown. I move closer, and a cockroach drops off the bureau and skitters across the floor.

I move into the kitchen and whisper to the VA nurse on the phone, “He lives alone?”

She answers, “He’s a widower for a number of years now.”

Bronson returns with the stair-chair and helps Mr. Robinson onto it.

“Careful with the legs,” Mr. Robinson says. “They ain’t doin’ so hot.”

The nurse makes me put the phone to his ear. “Don’t worry, Mr. Robinson,” she shouts. “You’ll be here soon.”

As we strap him in he starts telling us a story about being on a boat, but his Southern accent makes it difficult to follow. I shut off the apartment lights and ask about his house keys.

“They should be on the bureau,” he says. Then he looks at his watch. “My wife will be home from work soon. She’ll be here to let me in when I get back.”

I look around. “Okay, Mr. Robinson,” I say, and latch the door behind me.

Ms. Klopsis is an emergency medical technician for the FDNY. This column details her observations and experiences on the job. Some names and identifying details have been changed to protect the privacy of patients.