In an attempt to break the world record for going the most nights without sleep, the 28-year-old Los Angeles photographer claims he's stayed awake for the past 38 days and won't allow himself a wink of shut-eye until he's reached 40 days.
It's such a dangerous stunt that Guinness World Records wants no part in it. Shields has therefore enlisted friends to act as monitors and vouch for him when disbelievers inevitably dismiss him as a fool and a liar.
Nevertheless, by midnight Sunday, he'll end this marathon of sleep deprivation.
We at AOL Weird News question whether it's humanly possible to do what Shields says he's almost done. Nevertheless, in a telephone interview this week, he sounded very convincing -- and very tired.
"A lot of people say, 'This is impossible, you can't do this,'" Shields told AOL News. "If I was a normal person that slept every night, then I would agree with those people. But in my normal life, I only sleep one to two nights a week -- that's my normal. That's my every day."
So Shields decided to push his body long past the point of exhaustion by attempting to stay up for 960 hours. If he pulls off the stunt, he'll shatter existing records, which currently stand at 11 or 19 days without sleep, depending on whom you ask.
"I want to go for 40 days because I want to break the record so bad that nobody could ever get to it again," said the photographer, who's known for his eye-catching images of stars such as Lindsay Lohan.
If staying awake for 40 days is half as difficult -- or half as painful -- as Shields makes it sound, he could hold the record forever.
"This is the worst thing you could ever possibly do to yourself, and I would recommend no one do this," he said.
Though Shields is accustomed to functioning on less sleep than many people, he still trained his body to stay awake for days on end before the record attempt.
Thanks to the training, he said the first few weeks were easy.
"The struggling really started on day 25," he said. "I got a pretty bad fever out of nowhere. I ate like 50 Popsicles and the fever broke, but it came back on day 27 and I hit 103, 104, 105 degrees. When I hit 104 I sent my assistants to get bags of ice and I sat in the bathtub until it went down."
A few days later, he lost feeling in his legs.
"My leg started to go numb," he said. "It was bad for about three days, progressively getting worse and worse. There was a point where both my knees and down were numb. Then my whole right side was numb."
Thankfully, the numbness subsided. But by day 36, he found himself suffering from another unexpected ailment.
"I have to run to the bathroom every 10 minutes," said Shields, who swears he isn't drinking any coffee or any caffeinated beverages to help stay up. "I'm peeing like a 90-year-old man -- I can't stop myself."
Shields says he's also suffered severe headaches and eye aches, and his usually sharp memory is more frazzled.
Unsurprisingly, medical professionals aren't supportive of Shields' stunt.
Dr. Michael Breus, a psychologist who specializes in sleep disorders, told AOL News that the world record attempt is "highly dangerous and unhealthy," and noted that those who suffer from sleep deprivation can experience hallucinations, paranoia and other symptoms.
"I can only hope that he is in a controlled environment and is not driving, making any decisions or in poor health, as that would lead to certain problems," he added.
Breus said he doubts that Shields has stayed awake the whole time.
"In all likelihood he has slept," he said. "Even if he does not think that he has. Many people have what we call 'microsleeps,' where our brain will go into sleep for even a few seconds.
"I do not know of anyone attempting this length of sleep deprivation, and I am not sure it is even possible," the doctor added.
Shields agrees his stunt isn't possible -- for ordinary people.
"I'm a bit of an anomaly with the sleeping thing," Shields said. "If I was the average person, this would kill me."
His friends agree.
"Knowing Tyler as long as I have, I know he tends to be able to do a lot of things that most people can't do," said Jordan Fink, who is serving as one of about 10 spotters working in shifts to monitor Shields 24 hours per day.
Though Fink is confident in his friend's ability, he has his fears.
"It would be nuts not to worry about health or long-term effects," Fink said. "When he lost feeling in half of his body, I started to think, 'Well, this might be a bit much.' "
Shields said staying awake hasn't been a problem. He said that at no point during the past month has he even been on the brink of dozing off.
"It's not even a struggle to stay awake -- it's that everything else is a struggle," he said. "I took a shower this morning and it was the hardest thing I've ever done in my life. When the water was hitting me, I felt like I was being stabbed. I have to think about breathing, I have to think about moving."
But even if Shields manages to stay awake for 40 days, he might not wind up in any record books.
Guinness World Records spokeswoman Sara Wilcox says her organization hasn't recognized sleep-deprivation records since 1989, when it honored Robert McDonald for staying awake 463 hours and 40 minutes (about 19 1/2 days) in a rocking chair.
"[W]e do not recognize this category as victims of the very rare condition of total insomnia have been known to go without definable sleep for many years," she told AOL News. "Also, the British Association for Counseling and Psychotherapy warns that cumulative sleep loss can harm health."
Shields isn't happy that he won't be included in the record book but says he's not losing sleep over it.
"I don't think that you need the Guinness Book of World Records anymore," he said. "If they want to get on board and recognize it, that's great. I'm not doing it for them, I'm doing it for myself."
Shields isn't the first artist to push his body to the brink through sleep deprivation. In 1980, New York City conceptual artist Sam Tehching Hsieh punched a time card once an hour, every hour, for an entire year and documented the effects it had on his body.
But unlike Hsieh's, Shields' act of sleep deprivation isn't a work of art in itself. Throughout his world record attempt, Shields has been tending to his photography business as usual, scheduling shoots, taking photos and meeting with clients (though he says he's given up driving in recent days as a precaution).
"I'm still running my business," he said. "I have to go to meetings and explain to people that I haven't slept for weeks. I can't go into an office without sunglasses on because my eyes will water up from the fluorescent lights."
When asked why, Shields asks, why not?
"I want to prove to people that there isn't anything that's impossible," he said. "If you really want to do something and you set your mind to it, you can achieve it."
The biggest question in his mind now isn't whether or not he'll be able to stay awake until midnight Sunday -- the 40-day mark. It's how soon afterward he'll be able to fall asleep afterward.
"The longer you stay awake, the longer it takes you to fall asleep," Shields said. "There's a concern that when I hit 40 days, it might take me 20 or 30 hours just to fall asleep. We don't know."