For three days and two nights, illusionist David Blaine will enjoy an unusual view of New York City's Central Park -- one that can only be enjoyed from six stories in the air, while hanging upside down.
The magician's latest stunt, called the "Dive of Death," began 8:30 this morning as he was hoisted into position. The effort will reportedly culminate in Blaine dropping to the ground at 11 p.m. Wednesday.
Dr. Ronald Ruden, Blaine's physician, told ABCNews.com that when he first heard the name of the stunt, "It scared the crap out of me."
Considering the various health hazards Blaine may face as he hangs in the position for about 60 hours, Ruden's concern is warranted. He said the stunt will be all endurance -- no smoke and mirrors.
"How he does this I'm not 100 percent sure," Ruden said. "He seems to have the ability to use his mind to control his body to not experience pain and discomfort, as well as take away his basic drives to eat and sleep and defy his fear."
"We don't even know what the physiology of this is," he said with a laugh. "I hate that."
Blaine told "Good Morning America" today right before he was hoisted into the air that he always found images of Harry Houdini hanging upside down "compelling to look at."
Houdini dangled upside down wearing a straightjacket and tried to escape as quickly as possible, but Blaine's niche is testing his endurance.
"I always liked that idea of being upside down," Blaine said. "So I started experimenting on how long could somebody actually be put upside down. And there was no documentation of it. Nobody really had research on it. I invited doctors to kind of look and watch me as I was doing experiments. And although the dangers are high, I think there's a way to override that. "
Blaine said he has prepared for the challenges of the 2½-day hang by losing some weight, performing special exercises and practicing dangling upside down.
But there are certain health considerations that simple conditioning cannot address. During his ordeal, Blaine will not eat or sleep. He will urinate through a catheter. And doctors not involved with the stunt say there are definite risks involved with his attempt.
"He's practiced a lot, but I'm not sure how long he has done it," Ruden said. "I'm pretty certain that the longest he has done it so far is around six hours."
In particular, Ruden and other physicians agreed that Blaine will face multitude of risks associated with the unusual increase in blood pressure that Blaine will experience.
"The heart is centered pretty close to the head, so it does not have to pump blood very high," Ruden said. "When you flip it around, though, the toes are four and a half feet from the heart. So the heart has to pump blood to a higher altitude than what it is used to."
This, in turn, means a higher blood pressure. With this risk come a number of possible problems -- not the least of which are stroke and possible blindness as the blood pressure in his eyes increases.
Blaine said doctors will be on hand during the stunt, checking for brain hemorrhaging and stroke and making sure his vision stays clear.
"Certainly, [the stunt] could potentially be very dangerous because the brain relies on gravity to allow blood to flow out of the skull," said Dr. Wendy Wright, assistant professor of neurology and neurosurgery at Emory University Hospital in Atlanta.