Wim Hof, a 57-year-old who goes by the nickname “The Iceman,” holds 20 Guinness World Records for withstanding extreme temperatures. He’s run barefoot marathons in snow, dunked himself naked in freezing lakes, and climbed Mount Kiliminjaro dressed only in shorts. Today, he instructs classes in the Wim Hof Method to students like surfer Laird Hamilton, claiming that exposure to cold, meditation, and special breathing techniques can essentially hack our immune and nervous systems, shedding pounds and improving health and energy.

A few years ago, investigative journalist Scott Carney flew to Poland to meet Hof, planning to expose him as a charlatan or madman in a piece for Playboy. “He seemed to be claiming superpowers,” recalls Carney. “Like conquering the world’s tallest mountains with no cold-weather gear, controlling his body temperature and immune system at will. I’d built my career debunking men like him.”


[quote position=”left” is_quote=”true”]Our lifestyles are just too antiseptic and comfortable now.[/quote]

Instead, Carney says that he dug into the science driving Hof’s health claims and found that he was the real deal, zeroing in on simple but profound techniques that allow us to turn the extremes of our environment to condition our bodies and renew our lost evolutionary strength. After meeting Hoff, Carney says, “I hiked to the summit of Mt. Kilimanjaro without a shirt. I sat on the snowy bank of a river until the ice melted around me.”

After turning his experience into the book What Doesn’t Kill Us: How Freezing Water, Extreme Altitude and Environmental Conditioning Will Renew Our Lost Evolutionary Strength, out this month from Rodale Books, Carney spoke to GOOD about just how healthy it is to go extreme.

In 2013, you first flew to Poland to meet Wim Hof as a skeptic. Can you tell us about those early days?

I was living in Long Beach, California, had a belly paunch, backaches, and thought my days of youthful adventure were fading fast. Then I saw a picture of a nearly naked man sitting on a glacier. I thought maybe Hof had some very special physical abilities—perhaps genetically bestowed—to be able to endure the ice. But when he started suggesting he could teach people the same techniques, I was wary. I didn’t go to meet him with the intention of changing my health. I went to expose him as a charlatan. But instead I learned that his techniques are teachable, and that he has unlocked some ways for us to use the environment to stimulate our innate immune system.

In your book, you talk about the scientists who have studied Hof’s abilities. What did they find out?

In 2007, at the Feinstein Institute for Medical Research on Long Island, Hof was studied by Kenneth Kamler, a doctor who has worked on Everest. Hof was connected to heart and blood monitors and immersed in ice. Hof stayed in the ice for 72 minutes. His heart rate went down to 35 beats per minute. His breathing slowed down to once every few minutes. His core temperature initially declined a few degrees, but then rose again. Later, Peter Pickkers, a research scientist at Radboud University Medical Center in the Netherlands administered a harmless toxin (one made by the common E. coli bacteria found in our gut) to Hof. Ninety-nine percent of healthy people react with flulike symptoms to the toxin before their body realizes it is actually not harmful. Hof did not react with flulike symptoms, he had only minor headaches. Blood drawn while he was meditating remained resistant to the toxin for six days after it had left his body.

You point out that Hof might have unique abilities, perhaps some of them genetically bestowed.

Hof’s ability to withstand long exposure to cold might be partly due to the fact he has larger than usual amounts of heat-generating brown fat. His identical twin brother André also has the same high amount. They were both studied by scientists in the Netherlands.

But he was actually able to train volunteers to regulate their immune systems, right?

Yes, he trained twelve healthy volunteers in his method. They received injection of the toxin, and the trained volunteers were able to keep the body’s reaction at a far lower level than their untrained counterparts. An anti-inflammatory molecule called interleukin-10 increased more rapidly in the trained volunteers, while inflammatory molecules were lower.

How would you describe your health today, after learning Hof’s method?

I can’t claim that what I’ve experienced will apply to anyone but me, but my metabolism has changed pretty radically. I used to wear size 36 pants and now I wear size 31. I was given a treadmill test by Rob Pickels of the CU Sports Medicine and Performance Center in Boulder, Colorado. My bloodwork showed that when I exercise, I burn fat, not carbohydrates. I’ve added the equivalent of seven hours of exercise to my weekly routine, but actually my total exercise is about three hours a week. I was always afflicted by painful mouth canker sores, since I was a kid. After using Wim’s cold-exposure techniques, I haven’t gotten a single canker sore. That’s a small thing, but I’ve met people who have reversed rheumatoid arthritis or Crohn’s disease using his approach.

What is the scientific explanation for all of this?

We have this underlying biology that’s very adaptable and survival-oriented, but these days we are cocooned in comfort and we don’t activate it. So we’ve broken our fundamental biological links to the world around us. Indoor plumbing, heating systems, grocery stores, cars, and electric lighting now let us control our environment so thoroughly that we can live in perpetual homeostasis. But we evolved differently. We evolved to survive variations in our environment.

[quote position=”right” is_quote=”true”]In one study, overweight diabetic men were put into a cold room and their insulin resistance improved.[/quote]

Think of our ancestors who mounted expeditions across frozen mountains and parched deserts with only a whisper of technology to aid them. Simply reintroducing some common environmental stressors can bring back some of our lost evolutionary vigor. There’s a hidden biology we can tap into. We need environmental and physical variations that invigorate our nervous systems. We are living today with an evolutionary mismatch. Ray Cronise, a former NASA scientist, says we’re overlit, overfed and overstimulated.

What does cold do for us?

First, it activates and increases your brown fat (BAT). BAT is a type of fat that the body uses to generate heat. So brown fat boosts our metabolism and burns calories. It stimulates your body to generate more muscle mitochondria, the energy powerhouses inside your cells. In one study, overweight diabetic men were put into a cold room and their insulin resistance improved.

Why would someone’s immune system improve?

We don’t have all the science yet, but I can speculate that it’s because your nervous and immune systems are connected. That’s been proven scientifically, and we also know it from the simple fact that when you’re in better spirits it’s harder to get sick. But if you’re depressed and stressed you’re likelier to come down with a cold. The way I look at it, our lifestyles are just too antiseptic and comfortable now. These cold showers and strenuous breathing techniques essentially give our immune system something to occupy it so it doesn’t turn on itself.

[quote position=”full” is_quote=”true”]You have to realize that your fear around this momentary discomfort—a discomfort that will definitely be there—is mostly in your mind.[/quote]

What is your routine these days?

I do his deep-breathing routine for 15 minutes every morning. The technique is outlined in my book, but it involves multiple rapid breaths followed by breath retention. I do 50 pushups while holding my breath. When I get in the shower, I expose myself to one minute of cold water at the end. The intensive cold shower or ice water activates your nervous system immediately. I keep the temperature of my home in the low 60’s. Just keeping the temperature of your home low is like doing a low-grade workout all the time. Your body has to work a little to keep warm. You can actually lose weight by dialing your thermostat down like that. And I run outside shirtless two or three times a week, no matter the temperature.

How did it feel climbing Mt. Kilimanjaro in shorts?

It was awesome and exhausting, but very liberating. The interesting part is not being shirtless. The interesting thing is the speed at which we did it, which was five times faster than the normal ascent. We did it in only 28 hours. Usually people go slowly because they have to acclimate to the altitude change. The peak is around 18,000 feet. Forty percent of climbers fail because of acute mountain sickness. In fact, some mountaineers called our climb a suicide mission. But the key was that we compensated with Wim’s breathing method. His method increases the rate of respiration and adds more oxygen to your tissues, and we did the breathing technique long before we had to. So we had enough oxygen in our systems to quickly climb. If you apply that concept to regular exercise, you want to breathe heavily before you get to the maximum exertion, before you feel you have to catch your breath.

In your book you say, “I don’t like to suffer. Nor do I particularly want to be cold, wet, or hungry. If I had a spirit animal it would probably be a jellyfish floating in an ocean of perpetual comfort.” Most of us are like you. What do you say to those who’d like to feel healthier, but shiver at the mere thought of getting icy water?

You have to realize that your fear around this momentary discomfort—a discomfort that will definitely be there—is mostly in your mind. If you’ve gone through your whole life and never been exposed to big temperature variations, then experiencing cold is going to be like going to the gym your first time. Of course it’ll hurt—I’m not going to sugar coat that for people.

But what’s exciting is that you’re suddenly opening your body to a new type of experience, and you will see very rapid changes in your physiology. Pretty quickly you’ll start to feel euphoria as you release all these hormones like cortisol and norepinephrine. It’s like a runner’s high. It’s a natural response.

What’s your final takeaway?

No environmental extreme induces as many beneficial changes in human physiology as the cold does. Use it.

  • New Russian research suggests that the human lifespan could be up to 156 years
    Photo credit: CanvaResearchers found what's preventing us from living longer.
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    New Russian research suggests that the human lifespan could be up to 156 years

    Humans can live much longer if certain barriers are addressed.

    According to the Guinness Book of World Records, the oldest person lived to the ripe age of 122 years old. Such a lifespan is an incredible feat, but what if the average person could beat that record by 34 years? Recent research done in Russia has led scientists to believe that the average human lifespan could be up to 156 years.

    The researchers at Skoltech Biomed Technologies Center developed a mathematical model that allowed them to “switch on” a variety of aging mechanisms. This allowed them to calculate a human’s lifespan where mortality risk never increased with age. After experimenting with different scenarios and conditions, they found the biggest barriers to longevity were caused by non-renewable tissues and somatic mutations.

    What are these barriers against longer life?

    Somatic mutations are DNA changes within a cell. They accumulate over time during a human’s life and cannot be reversed with any existing therapy. These DNA errors that pile up in our cells contribute to the aging process.

    Many human organs like the liver and skin continually replace cells and regrow damaged portions of themselves. However, there are two organs that can’t do this: the brain and the heart. Brain tissue (neurons) and heart tissue (cardiomyocytes) cannot regenerate. This proves to be the most prominent biological limit that shortens our lifespans. This explains why issues like dementia and heart disease are prominent causes of death and morbidity later in life. Since those organs’ tissues don’t replace damaged cells, they’re prone to irrevocably decline over time.

    “The key finding of the study is the discovery of substantial differences between tissue types. Neurons and cardiomyocytes, which lack the ability to divide, turned out to be the main limiting factors: when all other causes of aging are eliminated, somatic mutations alone reduce the theoretical median lifespan from 1,759 years (for a hypothetical non-aging human organism) to 156 years,” said Evgeny Efimov, a research intern at the Skoltech Biomed Technologies Center, researcher at AIRI, and one of the key authors of the study.

    This suggests that somatic mutations and DNA damage is what ultimately prevents humans from living indefinitely, even if our brains and hearts regenerated cells like other organs.

    So what’s next?

    Now knowing these biological limitations, the researchers hope to study other areas of aging impacting the human lifespan that could plausibly be reversed. This includes mitochondrial dysfunction, telomere shortening, epigenetic drift, and loss of proteostasis. 

    The hope is to have a clearer priority list of issues for future therapies to tackle. This is not just to possibly extend life, but to improve lives in general. By developing a fully comprehensive theory of aging, Skoltech hopes to pinpoint which aspects of aging are within our scope to address. After all, thoroughly studying each puzzle piece that makes up human life gives us a better understanding of the whole.

    Of course, other impactful factors in a person’s lifespan can be addressed today. As most know, things like diet, sleep, and exercise are among them. A person’s living environment can also negatively impact their lifespan if it doesn’t have clean air, access to clean water, and so on.

    For now, the best method for living long is to follow instructions from your physician. Whether you make it to 156 years or not, living well is best for whatever time you’re given.

  • Screen time guidelines for kids and adolescents have shifted as research paints a more nuanced picture
    Photo credit: PeopleImages/iStock via Getty ImagesWhat kids are doing on tablets seems to matter more than how long they use them.

    Concerns surrounding young people’s screen time are widespread.

    Australia became the first country to ban social media for users under 16 in December 2025, and DenmarkFrance and the U.K. have since announced similar restrictions to begin this year.

    In the U.S., as of mid-2026, more than 30 states have passed laws banning or restricting cellphones in K–12 classrooms; in 2023, the U.S. surgeon general issued a formal advisory on social media and children’s and adolescents’ mental health; and bestselling books tell parents that smartphones are “rewiring” their children’s brains.

    These concerns and policies are part of a quickly changing national and international conversation around how young people spend time on screens and its relationship to their overall health and development. My reading of the mounting research on this issue across disciplines is that the popular narrative blaming screens and smartphones for an adolescent mental health crisis runs well ahead of the current evidence.

    I study adolescent digital media use and its influence on social, emotional and academic outcomes. A growing body of research suggests that one-size-fits-all solutions are not the answer and that managing appropriate use of digital media needs to take into account a child’s developmental milestones, how parents and adults around them use media, and the ways kids use it to connect and learn with friends and family.

    Screen time: From monolith to multifaceted

    Wide adoption of digital media and the internet broadened the range of experiences young people could have online. At the same time, the digital age introduced newfound uncertainties. As with the advent of radio, comic books and arcades, adults worried about how children might interact with or be affected by internet use.

    In response, the American Academy of Pediatrics first recommended in 1999 that parents and caregivers keep children under 2 away from screens. In the decades since, professional guidance largely treated children’s media use as a behavior to be mitigated.

    Policies introduced by the academy in 2013 and 2016 continued to advise that school-age kids and adolescents – those ages 5 to 18 – be restricted to no more than two hours of “entertainment” screen time a day. The goal was to curb risks associated with heavy media use, among them disrupted sleep, online safety, cyberbullying and physical inactivity.

    Originally created for young people’s engagement with stationary media that tend to be confined to one room or context – for example, watching television – these hourly limits became outdated with the integration of smartphones and other digital devices into everyday life. Compared with watching television, online media was far more difficult to track and define, and more nuanced in its use.

    Developmentally beneficial activities such as educationsocializing and leisure have come to rely on the internet to extend and maintain face-to-face connections. Remote schooling and social distancing during the COVID-19 pandemic only accelerated this digitization of daily life.

    In my view, adopting strict time limits and restrictions could pose risks to children’s well-beingautonomy and development, for example, by harming adolescent self-esteem.

    The latest guidelines

    In January 2026, the American Academy of Pediatrics retired its decade-old framework that had largely organized its advice around hourly screen limits. The new policy statement on children, adolescents and digital media diverges from this blanket approach. Instead, it suggests parents consider the larger picture in which this media use exists rather than lumping all screen use together.

    Similar to the World Health Organization’s 2019 guidance for children under 5, the American Academy of Pediatrics still advises that parents avoid screen media for children younger than 18 months. This recommendation is largely because extended use by children by themselves can be problematic for many young children, crowding out important developmental milestones.

    Both the World Health Organization and the American Academy of Pediatrics also recommend that when children under 24 months use screens, they should be limited to content and devices that encourage children and caregivers to interact. For ages 2 to 5, screen time – including TV and interactive apps on devices – may be extended to more solo use, provided it’s high-quality digital media designed around learning goals in mathematics and reading. But recreational use should be limited to roughly an hour per day.

    For school-age children and teens, the newest guidance has begun to step away from fixed screen time limits and asks families to weigh online activity in the context of everyday life.

    Doing so recognizes that a child’s digital experiences are shaped by diverse factors rather than the hours spent online. Current guidelines call on caregivers to distinguish among types of media, from television and social media to video games and interacting with artificial intelligence chatbots. They also call for taking into account a child’s individual characteristics, such as their interests and personality, family members’ own use of screens, and the type of content children are spending time on.

    Rethinking screen time

    Moving beyond strict screen time limits includes questioning the kind of digital activities kids and adolescents participate in. Do the activities encourage time spent interacting with others online, which can help young people develop important skills and competencies?

    Scrolling an algorithm-based, auto-playing video feed likely does not equate to the same opportunities as video-chatting with friends, creating digital art or working with teammates in a multiplayer game. Research suggests these different uses relate to development in different ways and can help kids develop varying skill sets pertaining to everyday life and schooling.

    Indeed, a large review of current research found that young people who take part in a range of digital activities, such as browsing the web, online gaming or interacting on social media, show positive associations with social connection, identity exploration, civic participation and learning.

    A woman and two small children look at tablet screen
    Parental involvement in young children’s screen time has developmental benefits. Cultura Creative/Tetra images via Getty Images

    Using these guidelines at home

    The current evidence suggests parents and caregivers are best positioned to be digital instructors. Cutting children off altogether can carry its own risks for social and emotional development. Caregiver mediation of children’s screen time can produce widely different outcomes and effects, depending on whether the guidance is supportive or controlling.

    Considering your own digital media use is the first step: Are family members engaging in problematic or heavy media use that children in the household might emulate? What applications and uses are most common in the family, and what positive or negative effects might they have, depending on the child’s age? How could these digital activities be safely integrated with other everyday experiences to increase their benefit for children? Conversely, what online time might be better spent on face-to-face experiences?

    The American Academy of Pediatrics’ Family Media Plan tool turns these ideas into concrete questions. For example, it recommends working out what each child needs from digital technology, what activities screens might be crowding out, and where their family or household can build in screen-free time. The recommendation is to talk with each child about why they are drawn to particular apps or online activities, what they encounter while browsing, and what might be lost when kids bring phones to gatherings such as mealtimes.

    The debate over young people’s screen time is not going away. But the most up-to-date guidelines, and the growing body of research behind them, make a strong case for a more holistic approach. The guidelines treat digital media as a complex, diverse and evolving environment that children need to learn to navigate in the digital age. The risks and rewards depend, as with any developmental setting, on the child, the content and what online time might be crowding out.

    This article originally appeared on The Conversation. You can read it here.

  • ER doctor and mom sets the record straight for parents of kids with e-bikes and e-scooters
    Photo credit: CanvaA boy rides an e-scooter, left, while a girl is examined in an emergency room.

    An emergency room doctor and fellow mom has been noticing a troubling trend: Many parents are giving their kids something more powerful than bicycles to get around the neighborhood. As a result, she’s seeing more children come into the ER with injuries sustained in e-bike and e-scooter crashes. She recently went online with a plea to parents and young riders.

    Dr. Meghan Elizabeth Beach Martin, known online as Dr. Beachgem, posted a video in her scrubs discussing her concerns after seeing so many children come into the hospital with e-bike injuries during the summer months. She’s worried that too many kids and parents don’t understand the proper safety precautions. As a mother herself, she even questions why children are allowed to ride these devices at all.

    In the video, the doctor explains that some e-bikes can reach speeds of up to 28 mph. She says that if an e-bike goes any faster than that, it’s technically classified as a motorcycle. At those speeds, she regularly sees children with traumatic injuries and broken bones after hitting bumps, cracks in the road, or other vehicles. Many of them aren’t wearing helmets or protective pads, and some are even riding barefoot, making their injuries even more severe. Martin’s video has gained traction on Reddit and elsewhere online.

    E-bikes and e-scooters, examined

    Martin isn’t the only professional seeing a growing problem. The American College of Surgeons reports that there are more than 20,000 e-bike-related injuries each year. Meanwhile, a University of California, San Francisco study found that e-bike injuries doubled annually from 2017 to 2022. The same study found that e-scooter injuries increased by 45% each year during the same period.

    Before riding an e-bike, it’s important to follow proper safety procedures. Make sure you and your child understand your area’s laws regarding e-bikes, including any minimum age requirements. Always wear a helmet and other protective gear when riding. Consider choosing an e-bike with safety features such as motor-interrupt brake levers and disc brakes. These are just a few of the many safety tips experts recommend.

    The U.S. Consumer Product Safety Commission has similar safety tips for e-scooter riders. Wearing a helmet is one of its top recommendations, along with taking other basic precautions. The agency also recommends checking the brakes before riding and slowing down for bumps, cracks, and other road hazards.

    The vast majority of e-scooters and e-bikes are designed for only one rider, so avoid doubling up. Although laws vary by state and locality, wearing more protective gear is always the safer choice. Riders should also review local e-bike and e-scooter laws to make sure they are operating the vehicles safely and legally.

    A little research goes a long way toward making sure you and your children can ride safely. It’s also important for parents to understand that many e-bikes and e-scooters can travel at speeds that make them very different from a traditional bicycle. The last thing you want is for you or your child to become another emergency room statistic.

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