Dr. Eben Alexander, a neurosurgeon, calls himself a scientist who had "always believed there were good scientific explanations for the heavenly out-of-body journeys described by those who narrowly escaped death."

That was until 2008 when a bout with a rare bacterial meningitis put him into a coma that lasted seven days. During that time he experienced his own near-death experience, or NDE, that he has turned into a book, "Proof of Heaven: A Neurosurgeon's Journey into the Afterlife," due out Oct. 23.

As part of the advance publicity for Alexander's account, he wrote an abbreviated account of his experience in the Daily Beast .

Alexander says that while he's not the first to have experienced an NDE, he claims to be only one who has experienced out-of-body consciousness while their cortex was completely shut down and their body was under "minute medical observation" for a week.

"There is no scientific explanation for the fact that while my body lay in coma, my mind — my conscious, inner self — was alive and well. While the neurons of my cortex were stunned to complete inactivity by the bacteria that had attacked them, my brain-free consciousness journeyed to another, larger dimension of the universe: a dimension I’d never dreamed existed and which the old, pre-coma me would have been more than happy to explain was a simple impossibility."

He goes on to describe a place full clouds, butterflies and a beautiful lady who guides him on his journey and tells him that he is loved, has nothing to fear, can do no wrong.

According to Alexander's account: “'We will show you many things here,' the woman said, again, without actually using these words but by driving their conceptual essence directly into me. 'But eventually, you will go back.'”

Coincidentally, a Canadian filmmaker is debuting "Hellbound," a low-budget documentary that explores these questions: Does hell exist and if so, who goes there?

"(Kevin) Miller's faith journey has taken him through Mennonite and evangelical churches to his current Anglicanism, where he embraced a gentle view of hell before he made the film: universalism, which doesn’t consider hell a place of eternal torment and holds that all souls will be saved," according to Religion News Service.

Miller also talks to traditional Christians who dismiss such beliefs as nonbiblical.

“If there is no ultimate justice and no hell as a place of just punishment, then Hitler got away with it and God is wicked, in the same way a judge is a criminal if he turns a blind eye to a murder,” evangelist Ray Comfort, who gets significant screen time during the 85-minute documentary, told RNS.

Most scientific skeptics dismiss all notions of heaven or hell, and a couple of them piled on Alexander, saying he's as dillusional as other religious people who cling to their NDEs as evidence of their faith in an afterlife.

"What Dr. Alexander and his PR people claim is that his description of the afterlife is more authentic because he is a neurosurgeon. But when there is no evidence except the word of the beholder, a scientist's accounts are no more reliable than those of anyone else," wrote Colin Blakemore, a professor of neuroscience and philosophy at the University of London, for the Daily Telegraph.

And Victor Stenger blogged in the Huffington Post that just because NDEs can't be explained scientifically doesn't make them true. He also argues that those experiencing NDEs haven't provided any verifiable evidence that what they claim to have experienced actually happened.

"Near-death experiences have been studied for over 30 years. Almost every year or two a book appears claiming incontrovertible proof of the afterlife based on NDEs. They are usually instant bestsellers. But they never convince anyone except those who want to be convinced because none present anything more than personal anecdotes such as those provided by Dr. Alexander. And, 'anecdote' is not another name for 'data.'"

Alexander wrote that he anticipates such skepticism of his story by the scientific community. But he says his experience has taught him that relying solely on the spiritual or the scientific as the road to truth is too simple.

"The plain fact is that the materialist picture of the body and brain as the producers, rather than the vehicles, of human consciousness is doomed. In its place a new view of mind and body will emerge, and in fact is emerging already. This view is scientific and spiritual in equal measure and will value what the greatest scientists of history themselves always valued above all: truth."