The last few weeks have been an unbelievable adventure. Sorry to leave you hanging on calories, but we’ll get back to that soon. The days have been full of travel ranging from an amazing party hosted by Tim Ferriss in San Francisco to hanging out with Wim Hof (aka iceman) and good friend Astronaut, Scott Parazynski. It’s an honor to interact with all of these incredible minds and we are all starting to see a real momentum in the power of the chill.
My home state (and city) were also hit hard by a the tornados and on a brighter note, the 4HB prescription of beans and cold showers were an unexpected preparation for 5 days of no power.
Chilling Out
If you haven’t seen my TEDMED video, it’s posted on the right. What an incredible opportunity to get the word out and it’s opened some fantastic doors. I want to give you a sneak peak at some exciting work to come. Many have asked for a “step by step” guide on how they can use the power of cool in their everyday routine and I’ve assembled an amazing team to bring that to you. You’ll see it posted here when it’s ready, but it’s extremely exciting to me. It was great to finally meet Wim Hof and his son, Enahm in person. We’ve been in communication for a while over email, facebook, and twitter, but spending 2 quality days deep in discussion was amazing. I got to watch Wim do a 1 hour and 15 minute full body ice immersion and it was really incredible. Wim insists anyone can do it with training.
I also want you to consider contributing to our research. On the right, I’ve asked a question about funding a thermal imager to document some of our crazy ideas. I put this up just after my last blog post (eeek – almost TWO months ago) and it hasn’t had much input. Please take just a few seconds to vote. I really want to create a community here and you have my promise that this is not going to be another fad diet scheme. As you will see this site is dedicated to a thorough exploration of what the human body can achieve. We’re going to look at the best we ALL can be, not just focus on the extreme or elite. We do have an unbelievable research team and you can bet we’re not putting our life-long reputations on the line for junk science. We have a drive to understand this and help ANYONE that choses to succeed.
From Weightless to Weight Loss

John Glenn, Scott Parazynski, Steve Robinson training on STS-95 Aerogel Payload with Principle Investigator, Ray Cronise
So Today, I want to introduce a good friend, former “office mate,” and an die hard adventurer: Scott Parazynski. He’s got the dream resume: Astronaut, MD, and Mountain Climber and that is just a START. Scott and I met in 1998 during a training session in preparation for his STS-95 mission along with crewmate, John Glenn. He was a backup to operate a science experiment I had proposed for the space shuttle on Aerogel; ironically, it was a extremely high tech transparent INSULATOR.
Scott and I spoke frequently in the time between his two Everest climbs, because he was the most knowledgeable person I knew on the subject of human adaptation and was willing to help me explain and verify my initial 2008 results. I’m sure in the “heat” of being cold on Everest he thought back a time or two about our frigid fat loss conversations, but Scott has been in extremely good shape as long as I knew him. he didn’t have any body fat to lose.
So let me turn it over to Scott to tell you a little about his adventure and experience with cool…
…Take it away, Scott.
A summit climb up Everest conjures up images of raging winds, breathless exhaustion and bone chilling temperatures, but rarely does one think of fad diets and dramatic weight loss. I had the (dis)fortune of spending two climbing seasons on Mount Everest, for a total of 4 months at extreme cold and altitude. Both of these seasons entailed dramatic weight loss, to the tune of 25 pounds (12 kilograms) each Himalayan foray. In the frequent keynotes I’m asked to give, I often make reference to the future New York Times bestseller I need to write, entitled “The Everest Diet!”
My first trip to Everest in 2008 was the fulfillment of a life long dream. As a climber since high school and a 17-year NASA astronaut, I’d seen and dreamt of standing atop the tallest mountain in the world for many years. My early heroes were all great adventurers, including the pioneers of space, mountaineering and deep sea exploration. Years later, my photo of Everest, taken from 250 miles up during Space Shuttle mission STS-66, is still perhaps the finest ever captured from space: it was a cloud-free day in the Himalayas on November 3, 1994, and the telephoto image reads just like a topographic map (you should post the image if possible with the article, along with one of me on the summit?). Staring at Everest from space and the framed photograph of the peak I kept above my desk, it was perhaps inevitable that I’d one day travel to the mountain for the ultimate physical and mental challenge.

Scott Parazynski on the Summit of Everest. He lost 25 lbs on this climb in part due to the extremely cold conditions
On the 59th day of my 2008 expedition to Everest, while at 24,500 feet above sea level on my summit push, I developed excruciating lower back pain. I later discovered that this was due to a ruptured disc in my lower back. Hobbling down outrageously steep terrain to base camp, and later flying in a medivac helicopter to Kathmandu, I eventually underwent surgery to remove a ruptured lumbar disc. With hard training and a personal inability to leave the job left undone, I returned to the mountain in 2009, and was successful in summiting on May 20th of that year.
The punch line of this story, however, has to do with the cold, and lots of it. BOTH of my seasons resulted in substantial weight loss, despite a concerted effort to consume mass quantities of calories, often in excess of 5000 each day. Granted, substantial physical exertion is required to climb the world’s tallest peak, and it’s difficult to choke down that many calories because of the hypoxia and poor appetite common at high altitude. That said, I certainly ascribe many of the LB’s I lost to the cold. To be clear, I went to the Himalayas each year a “hard body,” without much if any excess fat, so the pounds I ended up losing came from lean muscle mass. I’m convinced much of this loss was from the chronic cold conditions: shivering burns many calories, as does just keeping comfortable in less austere temperatures typical of mid-day and in-the-sleeping-bag rest on the mountain.
In closing, it’s no mystery to me that keeping cool means keeping lean. Not many people would go to the extreme of climbing Mount Everest to lose big time weight, but dropping the thermostat or swimming in cool water may just be the ticket to shed those unwanted pounds…
Thanks Scott! We’ll be hearing much more from Scott as we dive into some great self experimentation on thermal loading and weight loss.
In mean time, if you want to learn a lot more about Scott Everest/Space adventures and your chance at private space travel, please take a look at Scott’s TEDMED talk here:








Hi Ray!
Just read ‘Chillin At the Top of the World’ and I have a question. In a previous post I believe you touched on something where you mentioned that there is a difference when it comes to burning calories between being outside cold and the cold you experience in water, is this true?
Also, does Scott know of anyone who has tried to climb Everest that started the climb overweight and how did the climb affect their weight loss?
Thanks
Tiger
Los Angeles
Thanks Tiger,
Yes, water is about 24 times more thermally conductive than air and has 4x he heat capacity. Water grabs heat away faster than air and can hold more (meaning you likely won’t warm the pool).
I am sure most people are fit, but like you I am curious to know what percentage of caloric deficit is made up of muscle over protein if the person tends to have extra body fat. Maybe Scott will chime in…
Ray
Good day ray
Ive been experimenting with thermal loading for a long time now, im a personal trainer ( well unoffically will have to pay the outragous 4500 dollars to be licenced here in australia), this stuff is my life and i congradulate you and tim on the four hour body and what you have stumbled on here.
My life is about changing the world and also experimenting with my own body, im talking ten years in and out of sub 6% body fat.
Once my experiments have been concluded in future months i would very much like to correlate information and share information.
Looking forward to hearing from you.
Cheers
mark LCM for life
Great and thanks! Keep us posted. Love data…
Ray
Ok, so water is clearly better than air, but what about the amount of activity? For example, can you just soak in a cool pool or do you have to swim?
Water 78-84F you have to move. 70-78F have to move some unless in for a longer time. 60-70F transition to water that cab be hypothermic at normal exposure times. <60F be careful and you'll WANT to move to stay comfortable.
Good thermal loading at 80F with swimming, I prefer 76F
Ray.
Ray,
Do you have any thoughts or experience with using something like the Cool Shirt to attempt to have more prolonged cool expsoure?
Andrew
comes up a lot and I think that anything you can do to add to the thermal load creates progress. I just can’t quantify how much. There is a fine line between marketing hype and the real thing on these sorts of claims. I can tell you that a wet shirt in the wind can cause quite the chill!
try it. keep data. I’m curious too!
Ray
In your TED, you talk about blood-flow being restricted to the skin as the body tries to insulate itself (and protect the core) when exposed to cold. Doesn’t this reduce the effect of the load? If your core stays within a few degrees, shouldn’t you try to cool from within by drinking lots of ice water?
What are your thoughts on this?
Alex
good points, but it really is an oversimplification. Basically we are evolutionarily designed to give off heat. That is why room temperature is 77F/25C not 98F/37C. The best way to think about it is we are always giving off heat (newton’s law Hot->cold), but through vasoconstriction/dilation blood flow is shunted from/towards the surface. That increases and decreases heat transfer proportionally.
It turns out that process can be managed and controlled. THAT is where the big innovation is and in just a few more weeks, I am going to offer training on how to do it. The part of cold stress that isn’t so obvious is that just like weights stress muscle and muscle tissues grows, it turns out that environmental stress (like cold) is extremely important to our bodies.
So, what I did originally was “pile on cold.” It works through brute force, much like extremely low calorie/fad diets. Cold water is a factor, but inside/outside doesn’t matter quite so much. A more deliberate exposure as discussed in the 4HB has some huge advantages. I found through the last year that many have an extreme (unhealthy extreme) aversion to cooler temperatures. There seems to be a growing body of evidence that this really could be a significant oversight.
more to come…
Ray
I guess it’s just the tip of the Iceberg! My hope for drinking the cold is three-fold:
1) I don’t have a bathtub
2) tap water here in the Florida Keys is almost 80F
3) crazy electric bill to use A/C when it’s 90-95F outside
I’ve been 5lbs of fat away from goal for the last 3 months – looking for something to get me there. I’ll try the ice water and see if that gets me the rest of the way. I’ll commit to 3L of ice water a day for a month and see where I’m at.
Thoughts on spacing it out evenly or all at once?
Thanks Ray!
Spacing it out for safety. You can drink too much water if its too fast.
http://en.wikipedia.org/wiki/Hyponatremia
I don’t know the exact amounts or anything but 3 liters all at once sounds like a ton.
Hi Ray,
Just a quick question. I am experimenting with ice baths (water in the 40 – 50s for 30 min) daily. I am only going in waist deep due to the tub height. I notice I don’t shiver at all. But if I take a cold shower for 5 min in cold water I’m shaking life crazy.
Should I be focusing on getting my body to shiver, or just overall exposure with an ice bath?
Thanks in advance.
Me too! In fact I only have to get my hands and feet in the stream to induce shivering. Face, hands and feet are all dense with cold receptors. Been working on a few things the last few months that may be of help.
More soon…
Ray
Hello Ray,
Due to recent events in my life I have found it necessary to lose a large amount of weight. I’ve met a beautiful and incredible girl that I want to get closer to, but due to my heft, I’m currently 247 lb., I have a very hard time keeping up with her active lifestyle. When I first heard about thermal loading, I had a lot of questions about how to do it. I’m starting a reasonable diet and exercise program today, but I really need to boost the effects ASAP. Is an ice bath for 30 min a day 3 times per week really all there is to it or is there something else I can add? Please, I need all the input I can get. I need to lose at least 50 lb. within the next year.
Thanks for the great blog, and I hope to hear from you soon.
Gabe
Gabe
Right now (summer northern hemisphere)…swim. Find the coolest water you can find and swim. You’ll not
Only activate brown adipose tissue, but the combination of heat from activity and increase thermal load of the water will have a multiplying effect.
Caution: your body senses the load, so be prepared for a nutrient dense, calorically poor meal about 2 hours after swimming. That is when your hunger will peak and the wrong time to be planning a meal or hanging out at a junkfood place. You’ll blow the progress if you do…
On food equation, can’t beat plant based diet for rapid weight loss. Set all animal products and aside and reduce oils. It works everytime and extremely fast.
Ray
Can u give a round estimationof how many calories could be burned by an average man or woman sitting in a 76 degree tub of cold water for 30 min? Anyone?
At 28C and fully submerged you are (thermodynamically) at 2.4 times your resting metabolism rate. There is some evidence to believe that the effect of short term exposure has a longer term effect through an overall metabolic/circulatory response; this is analogous to your muscles growing due to stress of weight lifting or exercise.
My weight loss was primarily driven (I believe) by long term cool exposure – thermodynamic loss. Tim seemed to enduce the more root-metabolic approach. To do so you probably need colder water than 76F.
I’ve been working on a lab last few months to measure both.
Hopefully results soon…
Ray
Ok thanks so much. I decreased my water temperature to 56 degrees. It was so much colder, I almost didn’t get in. 🙂 lol
I’m targeting 50 degrees for 40 min 5 days a week Have you been able to see results at your temps?
Thanks Christopher
Keep me posted on it as well. Please use the tracking sheet at the PROGRESS menu above for tracking your results.
Ray
Great post Ray, I’ve just recently come across your work and have started to give it a go with cold showers every day and cold baths at the weekend. So far I’ve just been using cold tap water without adding ice (I don’t have easy access to large amounts of ice at the moment). I’m worried that it might not be cold enough, as I can quite easily manage 40 mins in the bath without much shivering other than the odd muscle twitch.
Your comment above about prolonged exposure to cold got me thinking about how this could be easily achieved by the rest of us. Has anyone ever tried some of the ice vests that athletes wear? They don’t seem to be widely available to consumers but just wondered if they were something you had ever tried, or think would be effective?
Thanks Ben
I think that the cold showers are good and if you can sit in cold water, adding Ice really shouldn’t be that big of a leap. Remember, before full shivering is “muscle tone” where the body sends out a stimulus to flex all muscles slightly. This is a lower level burn, but it’s expected that a recovery period of some type is taking place over many hours. The work with Wim Hof suggest that periodic cold stress does even more for the overall circulation system.
I’ve taken a lot of look at the vest subject, but to date, nothing quite fits the bill. If you see my TEDMED talk, you’ll see a quick reference to a patent that made claims about this.
I have been a bit quiet lately as a I finish my lab for more specific metabolic testing. I plan to look at all of these things again with more accuracy and better ability to fit the actual results with my math models on the subject.
stay tuned and THANKS for input.
Ray
Hey Ben,
I was looking at the vests too. I’ve been been doing ice baths for over a wek now. I find I don’t shiver much but I can tell my body is working long after I get out to bring my outer layers back up to temp.
SO far I’ve only bought a flexible gel neck wrap that you stick in the refrigerator. I find it doesn’t get cold enough so I’m back to just ice baths at about 50 dgrees for 30 – 45 min.
Thanks for your tips Ray. I look forward to hearing more about the vests.
Hey Chris, yea I agree it feels like it’s working for some time after the baths. Although I’m based in Osaka and it’s getting more and more humid daily so I feel like I’m heating up again quite quickly. I plan to start adding ice this week as Ray suggests to give that a go.
Hi Ray;
Two quick questions. What did you mean in an earlier post when you said “My weight loss was primarily driven (I believe) by long term cool exposure – thermodynamic loss. Tim seemed to enduce the more root-metabolic approach.” What is a root-metabolic approach?
Also, you mentioned that “On food equation, can’t beat plant based diet for rapid weight loss. Set all animal products and aside and reduce oils. It works everytime and extremely fast.”
I read 4HB and doesn’t this go against Tim’s studies suggesting you eat protein with every meal to keep down hunger and speed up metabolism?
Thanks
Tiger
Tiger
It’s anecdotal at this point, but we are on track to understand how these protocols might work. What we know is that the duration and temperature difference is not enough to simply drive pure thermodynamic loss. Hence, tim concludes in the book that he believed the loss rested in BAT (see BATgirl 1 & 2). I do attribute Tim’s personal results, I’m part, to BAT because he is 1) young and 2) maintained his weight.
In my case, I neither sat with ice, nor took ice baths. I lived almost exclusively at 55F/13C. I did a list of other things all in order to induce true heat loss. 1000 hours of “cool” exposure, combined with my in place diet/exercise program (Body for Life).
Through recent unpublished work, I’ve learned of a third mechanism that would contribute to both of our approaches and am pursuing that approach now. It also has implications well beyond wright loss and can induce increased endurance in even elite athletes.
So brief exposures seem to work on stimulating your body to dump energy through metabolic “tricks” and long term exposure (climbing Everest) is more closely related to your e getting cold sitting on the desk.
Hope that makes sense.
Ray
Ray,
I’ve read your chapter in the 4HB, and I watched you TEDMED talk. I’m interested in your ideas because I’m about 10 pounds over weight, and more importantly my metabolism does not suffer cold well. For example, if my office is cold for a few hours, I’ll get a headache.
I live in Japan, and we don’t turn on the heat at night during the winter, so I sleep with a hat and heavy blankets. I also probably can easily catch a cold because of being cold.
Anyway, I’m curious if I can change my metabolism, and if there is a good way to start that won’t affect me adversely. Perhaps you have a suggestion.
Thanks for what you are doing. It’s very interesting.
Sincerely,
Joseph Poulshock