Researchers have stumbled upon what they believe to be the oldest professional/medical case report of near-death experiences (NDE) - dating back to the year 1740.
The author of the 18th century report is Pierre-Jean du Monchaux (1733-66), a military physician from France.
He described a case of near-death experience in his book titled "Anecdotes de Medecine".
The description was recently found by French medical doctor and archeologist Phillippe Charlier.
NDE has been scientifically described as "a profound psychological event with transcendental and mystical elements" after a life-threatening crisis.
People who report NDE talk of awareness of being dead, positive emotions, out of body experience, the feeling of moving through a tunnel, communication with light, observation of colours of a celestial landscape, meeting with deceased people and life review, etc.
"The book itself was not an important one in the history of medicine, but from a historian's point of view, the possibility of doing retrospective diagnosis on such books, it is something quite interesting," Charlier said.
The book describes the case of a patient in Paris, who temporarily fell unconscious and then reported that he saw a light so pure and bright that he thought he must have been in heaven.
Monchaux speculated that NDE was a result of little blood in the veins in their skin, and abundant blood flowing in the vessels within their brains.
However, modern researchers think it is likely the NDE has been caused by the lack of blood flow and oxygen to the brain that puts the organ in a state of full alarm and causes the sensations associated with near-death experiences, Live Science reported.
The findings appeared in the journal Resuscitation.