Pet owners will freeze their dying animals to one day bring them back to life. Billionaire Peter Thiel is backing the technology to make it happen.

• Kai Micah Mills is a rare cryonics entrepreneur in the latest batch of Thiel Fellows.
• His startup Cryopets aims to establish a chain of animal hospitals set up to freeze pets upon death.
• He believes that scientific advances can one day revive people's frozen companions.

When he was 14, Kai Micah Mills brought home a long-haired tabby cat and named it Cat. Growing up in Utah, they were inseparable. Mills, a soft-spoken, antisocial teenager, had dropped out of high school and earned an income running Minecraft servers from his basement. He didn't have many friends, but he always had Cat.

Cat is getting on in years. But if his owner's new business works out the way he hopes, Cat will never die.

These days, Mills has turned his sights to something more macabre than gaming. He is a rare entrepreneur in the field of cryonics: the process of storing humans and animal remains at deep-freeze temperatures with the hope that scientific advances can one day revive them.

The startup he founded, Cryopets, aims to establish a network of veterinary clinics that provide regular check-ups and emergency care, and upon a pet's death, owners would have the option to preserve their companions. The pets would then be shipped to a Utah facility, where they wait in metal vats for resurrection day. In doing so, Cryopets embodies a "full-stack" approach to care, encompassing life, death, and the possibility of return.

Though the idea might seem far-fetched, Peter Thiel — the billionaire investor who's funded artificial intelligence, reusable rockets, life extension, and seasteading — would beg to differ.

In February, Thiel's foundation announced Mills and 19 others as the next class of Thiel Fellows. Each receives $100,000 over two years to start a company, on the condition they pause their college studies. Mills is one of the few high school dropouts ever admitted.

At 24, with a slim build and hair past his shoulders, Mills has spent the better part of a decade planning for a future where there is no death. Cryopets, he said, is part one.

Someday, he hopes to expand to human preservation, as the science matures and pet owners warm to the idea. "It's a gateway drug to humans," he said of his startup.

"In the end I'm interested in keeping people from dying," he explained, "not just for a little bit, but completely."

Mills' plan is starting to come together. He's spent the last year and a half fundraising, buying equipment, and assembling a scientific advisory board. Cryopets' waitlist now includes about 500 dogs, cats, rabbits, hamsters, and one monkey. Later this year, Cryopets will kick off the search to hire its first veterinarian and begin research into organ-warming methods.

The timing feels right to Mills. The longevity sector, according to a report by the British news outlet Longevity.Technology, clinched $5.2 billion in financing last year. Sam Altman poured $180 million into Retro Biosciences, which aims to extend the healthy human lifespan up to a decade. And Laura Deming, a venture capitalist focused on longevity, is quietly working on advancing organ cryopreservation. Deming's new startup, Lorentz Bio, hasn't been previously reported.

With backing from the tech world's top transhumanist, Mills now has to convince people to take a gamble on his animal hospital for immortal pets. And here's the rub: He may be long dead by the time they can be revived.

Forever young

Growing up in the Mormon church, Mills always figured he'd live forever. Even after he fell out of religion in his teens, he didn't give up on the idea of everlasting life.

On YouTube, he came across Russian millionaire Dmitry Itskov, who had sold his media empire and funded research with the goal of cheating death. "Eternal life not through faith but science," Mills said. "I really loved that approach."

For years Mills sat on the idea. He sold his server business at 16 and started another company, Branch, making virtual offices where workers moved around rooms like a video game. Branch rode pandemic trends to the tune of $1.6 million from investors like Homebrew and Naval Ravikant. But the company felt more like his cofounder's brainchild than his, and, in 2021, Mills left to dig into longevity.

He joined an incubator and spoke to many experts in aging, but his conversations left him with a sense of dread.

"We have such a long way to go to curing aging," Mill said. "It didn't seem like something that was plausible in my lifetime."

He started to think about how he could buy himself more time. Then he thought about Cat.

Why pets?

For any number of reasons, animals make better cryonics-guinea pigs than humans. It's cheaper to freeze pets because of their small size, Mills explained, and it avoids hairy legal battles. But their big advantage is that there's higher predictability around their deaths.

When a pet is close to death, it may be euthanized at an animal hospital, which is ideal for getting the body ready for cryopreservation. The process includes cooling the body in an ice bath, pumping out the blood, and replacing it with an antifreeze solution that prevents cold damage.

It's important, according to Alcor, a leading cryonics organization, to start the preparations shortly after death to prevent decay. "Longer delays place a greater burden on future technology to reverse injury and restore the brain to a healthy state," Alcor's website says.

"Humans don't get euthanized," Mills said. "We die in some sudden death fashion."

So, he decided to tackle cryonics for pets first.

The plan for Cryopets is to open an animal hospital for piloting this model of caring for pets in life and death, plus a storage facility. Eventually,it wants to partner with other hospitals, training them on how to prepare the bodies and then storing them at its facility.

Cryopets is not the first to market. The Cryonics Institute in Detroit, Michigan, and Alcor in Scottsdale, Arizona, will preserve the furry friends of its human members, for an additional cost that ranges up to $132,000. The price comes down if the person opts to have only the head stored. Cryopets, however,  will only offer full-body cryopreservation.

Mills hasn't figured out a pricing structure yet, but says pet owners will make a payment that covers their pet's storage for as long as necessary.

Insider asked Mills what happens when a pet's owner dies too. They might have arranged for their own cryopreservation, he explained, so they can come back at a future date with their pet. If not, Mills says Cryopets will put the frozen animal up for adoption. He imagines a time-traveling critter would be quite popular.

"Can you imagine," Mills said, "the line of people who would be more willing to take care of a cat from the 1800s?"