"Wim Hof’s technique of using physical discomfort—like ice baths—to improve mind and body is gaining popularity as it seeks scientific acceptance."

The Wall Street Journal reports.

In 2013, researchers at Radboud University Medical Center in the Netherlands found that 12 people trained by Mr. Hof and then injected with E. coli had milder flulike symptoms than an untrained control group. In 2019, tests indicated a significant decrease in inflammation in 13 people suffering spinal arthritis over eight weeks of training in breathing, meditation and cold exposure....

Mr. Hof’s career was born out of tragedy. He was in the Pyrenees working as a mountain guide when his wife died by suicide in 1995. “That’s the way it actually began—the real trial of my life,” he says. “We were left behind with broken hearts, four kids and no money.”

Swimming in icy cold water had for years been a pastime. Now, he found it stopped the rumination and pain. Cold water causes you to be in the moment, he says. “Going into the cold brought a lot of space, like stillness in my mind. It gave me moments of time to stop the agony, the why, why, why ten thousand times a day.”

"Their passion for nature cuts to the heart of what Scandinavians call friluftsliv (pronounced free-loofts-liv)."

"The expression literally translates as 'open-air living' and was popularised in the 1850s by the Norwegian playwright and poet, Henrik Ibsen, who used the term to describe the value of spending time in remote locations for spiritual and physical wellbeing.... Today, the phrase is used more broadly by Swedes, Norwegians and Danes to explain anything from lunchtime runs in the forest, to commuting by bike (or on cross-country skis when the snow falls) to joining friends at a lakeside sauna (often followed by a chilly dip in the water) or simply relaxing in a mountain hut. The concept is also linked closely to allmansrätten, the right to roam. Scandinavian countries all have similar laws which allow people to walk or camp practically anywhere, as long as they show respect for the surrounding nature, wildlife and locals....  Swedish data confirm that the amount of time young people are active outdoors has dipped slightly over the past three decades, with around 25% now spending time in the countryside or forest at least once a week, compared to 29% in the early 1980s."

From "Friluftsliv: The Nordic concept of getting outdoors" (BBC). That's a 2017 article. I got there after googling "friluftsliv," which I encountered in a new article, "One Tank Getaway: Late winter in Door County offers great food, welcome respite" (On Milwaukee).