WATCH: Bear Grylls Filters Natalie Portman’s Water Through His Underwear for ‘Running Wild’

by Lauren Boisvert

Natalie Portman learned a lot from Bear Grylls on the season seven premiere of “Running Wild,” including how to filter water through a pair of underpants. While hiking through the cliffs in Southern Utah’s Escalante Desert, Bear Grylls and Natalie Portman came across a pool of stagnant water. Grylls seemed excited about this, as it would add to their water supply after proper filtering and boiling. But, Portman seemed skeptical.

The water itself looked gross, to say the least. But, Bear Grylls seemed confident in it. If you know how to properly filter and boil water, it’s always best to replenish your supply wherever you find it. Even if it’s full of dead flies and sludge.

Video Credit: National Geographic

When it came time to filter the water, Grylls suggested, “We could use a sock, but then again you kind of need your socks. Underpants? Our sacrifice.”

“We’re going to filter sludge water through underpants?” Portman said in disbelief. Bear Grylls then pulled out a pocket knife and started cutting his underpants apart. Portman asked, laughing, “The water’s clean after it goes through your underpants?”

“Well,” Grylls replied, “what part of the underpants to filter it through,” to which Portman simply repeated, “Oh boy, oh boy.” She laughed, but also didn’t seem too thrilled about filtering dirty water through Bear Grylls’ no doubt sweaty underpants. But, “Running Wild” is all about learning and trying new things, and one thing we can say for sure about Natalie Portman is that she was willing to give it a try in this episode.

Bear Grylls and Natalie Portman Prove That Everything ‘Serves a Purpose’ on the ‘Running Wild’ Premiere

“When you’re in the wild, almost every piece of clothing serves a purpose,” Bear Grylls said in a voiceover. “Except maybe your underwear. That’s where the term ‘going commando’ originally comes from.” Natalie Portman laughed and joked through the whole ordeal of Bear Grylls taking his underpants off in the middle of a canyon, but she did politely avert her eyes.

Grylls explained more about the practice in the voiceover. “Commandos would often forego underpants in hot environments, and since my underwear is a luxury, it’s the perfect candidate to use for water filtration.”

Once Grylls had enough scraps of underpants, he laid it over the mouth of his water bottle. “This is…gross,” Portman laughed. “It’s less gross than that,” Grylls replied, gesturing to the bottle full of sludge water.

“That’s not a high threshold to start from,” said Portman. Grylls proceeded to filter the gross water through his underpants from one water bottle to the other. When Grylls takes the underpants away, you can see it’s full of junk and sludge from the stagnant pool. The water comes out looking a little brown, but much better than it had previously. And, we all learned a valuable survival lesson: your underpants are a sacrifice you have to be willing to make.