John Verrier checked into the emergency room around 10 p.m. Jan. 19 complaining of a rash, WABC-TV, New York, reported.
Hospital staff checked his vital signs and told him to sit in the waiting room until a doctor could see him. By 6:40 a.m., a security guard checked on the man and found him "stiff, cold and blue," a hospital worker whose name wasn't reported said.
The worker said it's likely Verrier had been dead for a few hours before his was noticed by the security guard.
"There's no policy in place to check the waiting room to see if people waiting to be seen are still there or still alive," the worker said, adding that Verrier's name had been called three times over the hospital's public address system.
Verrier's family said he had struggled with drug addiction but had been clean for months and living at home.
"No one should sit in the waiting room that long. I'm sorry, name calling over the loud speaker proves nothing, nothing," his mother, Susan Verrier, said.
The New York State Department of Health said it is investigating the incident. The medical examiner has yet to determine a cause of death, WABC said.