To maximize longevity, you might think it’s best to play it safe and stay cozy. But some scientists believe we should do the opposite, as exposure to extreme temperatures can trigger our bodies’ own defenses against the killer diseases of old age. Chris heads for the freezing Arctic with his brothers Liam and Luke to take on the ultimate cold therapy.

Chris turns to longevity doctor Peter Attia to find out how changing his eating habits can help his quest for longevity. Ironically, the answer is to eat no food at all for four long days. If he can bear the hunger, fasting will unlock his body’s own anti-aging powers and give Chris the edge he needs when he tries to hunt for his next meal … by spearfishing off the Great Barrier Reef.

As Chris bulks up for ‘Thor: Love and Thunder’ he needs to build a body that looks right for an immortal god. But, he also wants the kind of muscles that are scientifically proven to help him stay strong and healthy as he grows older in real life. Teaming up with extreme sports guru Ross Edgley, he trains for a grueling 100-foot rope climb challenge, changing him from an ornament into an instrument.

Chris has always worked to keep his body healthy; now it’s time to start looking after his brain. Neurologist Dr. Sharon Sha challenges him to go off-grid into the wilderness without a GPS or map. Teaming up with his buddy, First Nations artist Otis Hope Carey, Chris will need to tune into nature to navigate through Otis’ remote ancestral homeland. The hike stirs up Chris’s most precious memories.

Over the past year, Chris Hemsworth have been exploring the science of living longer, doing everything he can to hold back time. But whatever he does, sooner or later, aging and death will win. Now Chris is facing his most extreme and emotional challenge: three days in a retirement village while wearing an aging suit that turns the simplest activity into a Herculean task. He'll be carrying an extra 30 pounds around and shoes that will make him unbalanced, apart from glasses to see improperly and acoustic earmuffs. Later on, Chris is going to do a death-bed meditation. He’s testing the theory that the best way to combat aging and fear of mortality might not be to fight it but accept it,

Clarkson's herd of cows begins to settle in on the farm, but things immediately begin to go awry. The cows aren't keen on the idea of a fence and quickly escape, and when Clarkson attempts to wean the calves, they too break out and cause chaos. In addition, the new roosters brought in to help fertilize the soil also prove to be difficult to handle.