Hm, you surely mean this very well, but it seems the Wim Hof method also carries great risks:

All he is doing is hyperventilating, which is not a cure for anything. Hyperventilating causes hypocapnia, or a lowering of the CO2 levels in the blood. This can be followed by alkalosis and vasodilation/vasoconstriction.

Hyperventilating causes tingling, contraction of the hands and feet, flapping limbs, spasms, seizures and brief blackouts. These are all things seen in this video.

After that, the hypocapnia causes a person to be able to hold their breath for a long time, because CO2 levels tell the body to breathe when holding your breath. With low CO2 levels (hypocapnia), caused by hyperventilation, you have no CO2 telling you to breathe, so you feel like you can hold your breath for a long time, which is a false feeling, because your lungs would be burning like crazy if you had proper CO2 levels. Breath-hold divers use this trick.

The problem is that hypocapnia, while it lets you hold your breath for a while, deprives the brain of oxygen and hurts the body, even though you don't feel as much pain, due to lack of CO2. The brain uses up the pool of oxygen in the blood around it quickly, but the rest of the body uses oxygen more slowly. As you hold your breath, your brain stops getting enough oxygen after 60-90 seconds. If you keep holding your breath, thinking you are fine, you will eventually have no blood flow to the brain. Breath-hold divers are known to get shallow blackouts as a result, which causes many of them to drown.

Hypocapnia, combined with holding your breath, and subsequent shallow blackouts, will lead to alkalosis, or an increase in your blood pH, which causes neurological irritability, such as crying or getting mad, anxiety symptoms such as tingling, fast heartbeat, high blood pressure, cramping, dizziness or strange muscular feelings, as well as mental confusion, which is often interpreted as euphoria, or happiness, even though it is simply minor brain damage. People in this video exhibit these textbook symptoms, especially crying, anger, and then confused "euphoria". They are actually giving themselves anxiety by doing this. They only interpret it as "euphoria" because Wim Hof tells them it is euphoria and they believe him. However, over time, hyperventiliating + hypocapnia + breath holding + alkalosis will lead to severe anxiety/depression and permanent brain damage.

In the "choking game", some people choke themselves to deprive oxygen to get euphoria, and others hyperventilate, then hold their breath to cause alkalosis to get euphoria. What Wim Hof is doing is nothing more than the "choking game", a very dangerous and potentially fatal deprivation of CO2, followed by deprivation of oxygen through breath-holding and then a false sense of euphoria because of increased pH levels in the blood releasing chemicals into the body. Those chemicals cause vasodilation in the tissues and vasoconstriction in the brain.

Vasodilation in the tissues allows for increased blood flow through blood vessels, which can explain how you would supply excess heat to your fatty tissue to keep warm in cold weather. Vasoconstriction in the brain is not good. It is the opposite. And vasoconstriction, due to alkalosis side effects, since it is harming the brain, would cause the brain to release large amounts of adrenaline to save itself, thus explaining the surge of adrenaline. Vasodilation also helps to prevent immune disorders, which is why people are given vasodilators as medication.

Hyperventilating until you have hypocapnia is, like smoking, bad for you, but it doesn't necessarily kill you or shorten your life by more than a few months. A lot of people can tolerate hypocapnia and not die. Hypocapnia does allow for holding the breath without pain for a long time. Alkalosis does give a natural, sometimes "euphoric" high. And vasodilation can result in resistance to cold, protection from immune disorders and more adrenaline released into the body.

But, on the other hand, this technique will also, like the "choking game", lead to tingling, spasms, loss of blood flow to hands and feet, seizures, mood changes, crying, anger, confusion, dizziness, blackouts, oxygen deprivation in the brain, potential serious long-term brain damage, severe long-term anxiety/depression, and potentially death.

You'll notice that the people in this video, within 2 days, have mood changes, confusion, complaints about tingling and numbness in the hands and feet, and they are notably down, starting the video genuinely happy and enthusiastic and ending the video zombie-like, just sort of going through the motions, as depressed people often do.

Wim Hof seems to tolerate almost all of these symptoms with no ill effects. He also benefits from the Hunting Reaction, which prevents damage to the hands and feet in people who vasodilate and vasoconstrict in either cold or tropical weather over a long period of time. But he could still be described as depressed and, at times, quite confused. He may also have a lot more anger, depression, and other problems than he lets on.

Nothing about hyperventilation, hypocapnia, breath-holding, alkolosis, or vasodilation/constriction is going to cure anything. At best, it helps in deep sea diving, cold-weather endurance, maybe (but not for everyone), and offers some protection from frostbite and a few immune disorders, but only if done intensively for a long time. All of those benefits could be achieved easily without any of the horrible side effects of going through hypocapnia, alkolosis or vasoconstriction, things which carry dangers of depression, brain damage and death. Use an air tank for diving, clothing for cold weather, and take vasodilators or other medicines if you happen to get sick. Simple. No need for putting your body through a bizarre version of the "choking game".

The scariest thing here is the fact that people will try this without consulting a doctor or an intelligent person, just because they saw it on a YouTube video. Now you know why kids play the "choking game" and eat Tide pods. One person makes a video making it look great and everyone joins in with no questions asked. Not one person who tried this technique thought to ask, "Is breathing like this good for me?". The answer is ... not really.
Notes* - All 12 of the people, including Wim, had reactions to the bacteria in this video, they only had less of a reaction than the 12 in the non-Wim-Hof-Technique group. The doctors agreed that this was a short term benefit only and ultimately all of them would have ended up sick without the treatment that the hospital provided after the test. The guy with cancer died in 2 months, like his doctor said he would. Wim Hof took a group of his students to climb Mt. Kilimanjaro and claimed it a total success. In reality, Kloptdatwel.nl interviewed a person from the group and they said that half of the group was evacuated due to altitude sickness and several of the ones who made it near the summit were not in the photo because they had bad foot injuries and were in failing physical condition. Even Wim Hof didn't climb down Kilimanjaro. He was taken down in a vehicle because he had pain in his feet and swelling in his ankles. Het Parool, a Dutch newspaper, wrote in July 2016 that 4 men had died from the Wim Hof Method. Wim said he warned them of the risk in his workshop, but no one could verify that claim. La Presse, a French newspaper, contacted Wim's brother and performed tests on him, and without any breathing techniques he had the same results as his brother Wim. La Presse wrote that Wim's brother had extra fatty tissue that insulated him against cold naturally (genetically) and that he had increased adrenaline in his blood normally, without any techniques. La Presse stated that they believed Wim and his brother share a genetic trait that is not something a person can learn and that the breathing technique is quackery.
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