Cold Thermogenesis: Incredible Cold Shower And Ice Bath Benefits

Cold showers. Ice packs. Cold therapy. Ice baths. Cold baths. These are all names for what is called "cold thermogenesis".

Cold thermogenesis means exposing your body to cold so that your body must heat itself.

If you're thinking: "are you crazy? Exposing myself to cold intentionally?", I admit I'm a bit crazy in this regard.

And yet, the benefits of exposing can be life-changing.


Let's go...

This blog post thus explains all the benefits you can get with cold thermogenesis methods - such as cold showers and ice baths.

Want more cold thermogenesis methods? Receive a PDF with 3 additional methods:

Cold Shower And Ice Bath Benefits: Why Cold Thermogenesis Is Amazing For Fat-Loss, Energy, Well-Being, And (Mental) Performance


Cold showers. Ice baths. Walking in the freezing cold wearing just a t-shirt.


Well, I confess to doing all of them. Why?

Well, let's take cold showers.

Daily cold showers actually have huge health benefits.

The good thing is that cold showers won't even cost you any time or money. Simply put, you just slowly replace your hot showers with cold showers over time.

This article will explain cold can be extremely beneficial to you. I begin, however, with telling you about my crazy cold thermogenesis stories.

What does cold thermogenesis mean?

Cold thermogenesis literally means "cold that generates heat".

In plain English, you cool your body down. Your body then needs to increase its heat production to remain warm.

That cooling can be accomplished in several ways:

  1. cold showers
  2. wearing a t-shirt outside during the wintertime
  3. cold baths
  4. ice baths
  5. and more...


Did I say that winter is coming?

Let's begin...

Table Of Contents

My Crazy Cold Thermogenesis Stories
Cold Thermogenesis Basics
Winter Is Coming: A Tale About Cold Thermogenesis
Why Cold Exposure Is Not Stress (At Least, Not For Everyone)
What makes Cold Exposure Special?
How To Create Your Own Cold Thermogenesis Bath
Cold Showers: The Universal Cold Thermogenesis Application
Cold Thermogenesis Sessions: Determining The Right Intensity
Conclusion: Start With Low-Intensity Face Dunks And Cold Showers
Frequently Asked Questions


My Crazy Cold Thermogenesis Stories

Before telling you why cold exposure is so important, let me tell you about my background with cold.

It was November 2015. I'm in the garden. It's 2 PM, and I'm getting my daily dose of cold exposure and sunlight.

And of course - I'm in my underwear.

Just like in this picture:

Bart Wolbers tanning in the snow and cold

The garden is located 1,000 yards away from a public street with lots of traffic. Guess what?

My boss drives by.

One minute later, I get a text message about how I'm basically a crazy S.O.B. For months - even years - afterward, people have been talking about that moment.

And that's not the only crazy story...

The year before that, my fellow students got to know me as the guy who never wears any jacket, even deep in the wintertime. All-in-all, I've spent two entire winters just wearing a t-shirt. 

There are probably thousands upon thousands of other people who saw me without a jacket during that time. They must have thought I am nuts.

You must be thinking "why expose yourself to so much cold?"

Well, during the past few years, I've experimented with cold exposure to find out how cold influences my biology.

I've even taken hundreds of cold and ice baths in the garden. And during my time in college, I've wrote a systematic review about using cold baths for recovery after strength training.

During the last few years, cold exposure was basically a major part of my life.

This guide is the culmination of these few years of cold-exposure experience. I hope the guide will help you to understand cold exposure - or cold thermogenesis - on a deeper level.


Cold Thermogenesis Basics

Cold thermogenesis, cold showers, ice therapy, cold therapy, cold water immersion, cold exposure, ice packs, basically all refer to the same thing: 

Exposing your body to cold. 

You can expose your body to cold in different ways. Cold showers have become a well-known method. 

Ice baths are another method:

tub for cold thermogenesis(I'll show you how to create your own cold thermogenesis
tub for $400 in a later section of this article.)


Why does cold influence your biology?

Remember that when you cool your body, your body must increase its temperature to stay heated.

It's that simple... 

In other words, cold forces your body to stay warm. How does your body keep you warm?

Your body fat plays a major role in the production of heat. Your body actually contains several types of fat: brown, beige, and white [27; 28; 29; 63].

Brown fat, which is mostly located around your neck and back, actually burns white fat, which is located around your belly and hips, for fuel. Fat - as fuel - thus keeps your body warm.

Simply put, your bodyfat is fuel that is burned when you expose yourself to cold.

If you expose your body to cold often, the body will adapt. The more your body adapts, the better will you be able to handle that cold.

But why should you even care about cold thermogenesis?

Let's find out...


Winter Is Coming: A Tale About Cold Thermogenesis

This section will help you understand why cold thermogenesis is so integral to how we function as human beings - even today.

Yes, I'm claiming that cold thermogenesis is already part of your life.


The surprising answer lies in evolution. Stay with me to find out why.

Our tale to understand cold thermogenesis begins when life first evolved on earth.

Life was created about 4 billion years ago. Yes, that's 4,000,000,000 years. During many periods within these billions of years, temperatures on earth were much colder than our current climate [1]. 

Often, the environments were what is called "extreme". Even today, many species live in extreme environments, such as environments that are extremely cold [2; 34; 35].

You, as a human being, evolved from species that had to survive in the cold.

You see, a meteor hit the earth 65 million years ago. That meteor devastated the earth's climate for many years.

The energy released from this meteor was 100 billion times as strong as the atom bomb om Nagasaki.

Because there was dust everywhere, the earth became colder: sunlight could not reach the earth anywhere. 

The period after the meteor impact was basically like a nuclear winter.

On land, two types of species survived this period. The first type of species could keep their own temperatures high. The second type of species could fly, and could thereby get access to sunlight.

Why are these facts important?

Well, remember that the dust clouded out the sun. Land-based species thus needed to be able to generate heat to stay warm.

Dinosaurs became extinct. One reason for their extinction is that they could not cope with colder temperatures [80; 81; 82].

Contrary to the dinosaurs, the species you evolved from could cope with the cold.

Those species that survived became the basis for any evolutionary blueprint that is found in modern species.

What is an evolutionary blueprint?

Oversimplified, an evolutionary blueprint is a sort of "construction model" for a given species. Let me give an analogy here.

Almost every house had a blueprint before it was built:

blueprint that is an analogy for human beings

In the same way that a house has a blueprint (as a construction model), your species and all other species have blueprints as well.

The human species has an evolutionary blueprint.

Your current blueprint is thus derived from previous species in evolution.

The way those previous species could react to cold is still part of you today. Phrased differently, it means that your current "evolutionary blueprint" is influenced by the cold thermogenesis capacity that allowed previous creatures survive the meteor impact earlier in time.

Remarkably, what happened in evolution 3 billion years ago, or 1 billion years ago, still shapes how your evolutionary blueprint functions today.

In a sense, you thus have commonalities with life forms that still exist in the extreme cold of the poles:

an analogy for mammaliah survival 66 million years ago
Your evolutionary blueprint: still influenced by the time when
life existed in extreme conditions, such as exceptionally cold temperatures.


What implications does this have, to say that previous species' ability to deal with cold still exists in you?

Older life forms in evolution reacted in a certain way to cold - and so do you.

How is that reaction to cold thermogenesis activated?

When light becomes less available because the days become shorter, your body's signaling begins to react to temperature instead.

Let me give an example.

Let's say you're living on the Northern hemisphere, in a country like Canada, Norway, Germany, or Russia. In these countries, the length of the day will be severely limited around the wintertime.

During the wintertime there, your body will no longer predominantly use light signaling, but your body will use temperature signaling.

When cold water or cold air contacts your skin, that temperature signaling is activated.

That cold in your environment begins to affects your wake and sleep cycle [37]. That means that the light that enters your eyes becomes less important [6; 7; 8; 9]:

cold and light affect the circadian rhythm

 (Public Domain Picture. National Institute of General Medical Sciences -
Circadian Rhythms Fact Sheet)


In a previous articles - on ultraviolet light and blue light blocking glasses - you may have learned that the light that enters your eye is very important for your day and night rhythm, and wakefulness.

What did these articles tell you about light?

Oversimplified version: when sunlight (or artificial light) enter your eye, they wake you up.

But when you move closer to the poles during the wintertime, light is less available. When light is less available, this is when your body switches to temperature signaling [22; 23; 24]. 

So if you're living in Sweden or Russia, your body is meant to be exposed to the cold during the wintertime [10; 11].

Stay with me to find out why.


(Nerd section: That cold signaling pathway is never activated by modern humans anymore [3]. Why?

Because of what all modern homes have in common. There are three main reasons:

  1. modern homes are kept at a constant warm temperature
  2. modern homes have artificial light present 24/7
  3. people wear a lot of clothing whenever they leave their homes

These three reasons prevent your cold signaling pathways from ever being activated. You're thus living in a "warm" environment 24/7, without ever accessing the cold pathways in your blueprint. Our modern environment simulates summertime 365 days a year, with carbohydrates and high temperatures always being present).

What's even more interesting about cold exposure?

When sunlight is not present, you can use cold to make you feel good.

You see, cold thermogenesis can make you feel great in the same way that sunlight can. Cold increases the dopamine levels in your brain [12; 13; 14; 15]. 

Dopamine is a motivation and reward neurotransmitter that helps your brain function optimally. Dopamine also helps you think outside the box, bolsters decisive action, and allows you to see patterns.

Dopamine additionally aids in making better choices and helps you see the big picture in life.

If you don't let nature build your dopamine levels - either through sunlight or cold thermogenesis - then you'll automatically find other ways to raise your dopamine levels. These alternatives include porn, drug use, alcohol, sex addictions, watching too much television, or internet addiction.

The human body will do anything to feel good.

So, if the days get very short and dark at your location, you'll want to do this:

building dopamine in the wintertime with cold

(If possible, with little clothing!)

You'll learn about how intense these cold thermogenesis sessions should be later.

But why is cold so special?

Cold literally changes the (bio)chemistry in your body. That changing chemistry means that the laws that are applicable during "normal" warm temperatures are no longer valid [16; 26].

In plain English, the biology and chemistry in your body functions differently in low and high temperatures.

In terms of chemistry, human beings have two different types of metabolism.

One metabolism is active during long light cycles, such as the spring or summer. Another metabolism is active around the wintertime when it is dark, and acts on cold.

Human beings can tap into that darkness/cold metabolism with cold thermogenesis.

Put even stronger: human beings must tap into that cold metabolism when the days get very short.

Should you?


Cold thermogenesis does not need to be very hard though. A common question I get is "whether cold is really painful", or whether exposing yourself to cold is being hard on yourself.

That's why we'll now look at whether exposing yourself to the cold is stressful.

The answer might surprise you!


Why Cold Thermogenesis Is Not Stress (At Least Not For Everyone

You might think that getting in a cold shower or taking an ice bath is equal to adding stress to the body.

That's not always right.

If the intensity of the cold thermogenesis session is low, then the cold thermogenesis is not necessarily stressful.

Your stress hormones are not necessarily activated when you have a low to medium intensity cold session [30; 31].


To understand how cold does not necessarily add stress to the body, we'll have to look at our mitochondria in our cells:

cells and mitochondria plus additional organelles
Can you find the mitochondria in this cell [86]?


Mitochondria are the energy-producing "factories" of your body. Cold thermogenesis affects these mitochondria [44; 45].

How so?

When you are exposed to cold, the mitochondria in your cells have to increase their energy production.

At first sight, that increase in energy production seems like stress. However, that increase in energy production only seems like stress because there are two ways to look at this "problem":

  1. A chemical perspective, which pertains to biochemical reactions within the body.
  2. A physics perspective, that looks at how the fundamental processes of nature influence biology.

From the chemical perspective, adding cold to the body seems like asking the body to compensate for the initial stimulus. The chemical perspective might thus consider cold stressful. However, we're interested in the physics perspective right now. 


The physics perspective tells us that cold shrinks the proteins in your mitochondria.

Shrinking proteins means that these proteins move closer together. The closer these proteins are together, the higher the energy yield of the mitochondria.


Well, energy has to travel a shorter distance in your mitochondria.

In simple terms, that means that cold allows you to produce energy more efficiently.

How can one understand the word "energy" in this phrase?

Your mitochondria use electrons as their energy.

What are electrons? Look below. You can view them circling in this device:

electron visualized
Source: [4]


Electrons are a particle within modern physics.

From a physics perspective, the proteins, carbohydrates, and fats that you eat, can only be understood as "electrons" that are used by the mitochondria.

These electrons are transferred through your mitochondria to create energy.

From a physics perspective, when your mitochondria work more efficiently - due to cold thermogenesis - this means that these electrons create more energy.

To reiterate: with cold thermogenesis, the distance electrons have to travel becomes less, so that energy production is increased.

However, there's a second way in which your energy production is increased: cold up-regulates the electrical current in your mitochondria.

You see, the human body does not only rely on chemical reactions--the human body also works on electricity.

Cold thermogenesis increases that electrical current created in your mitochondria.

A previous blog post on talked about how you could use sunlight to increase the electrical current in your body.

The same is true for cold thermogenesis - cold can increase your electrical current as well

As long as the intensity of your cold thermogenesis sessions - such as cold showers or ice baths - remains low, cold is not stressful.

I would compare the intensity of cold exposure to taking a walk - a walk is also not inherently stressful.

Whether cold is actually stressful depends on your current health status. More on that later.

(Nerd section: let's consider why cold is not always stressful. Cold thermogenesis is thus not (just) hormetic. In other words, cold thermogenesis is not just an adaptation to a stimulus within an organism, but cold thermogenesis has biophysical effects. From a physics perspective, the shrinking of the proteins in the human body, the increased electrical current, cold exposure has effects on your health that are not hormetic in nature. A third mechanism that is not treated here is the expansion of water (due to the cold) - which increases the battery capacity for infrared and ultraviolet light, which are used as energy in your mitochondria).

Let's first consider why cold thermogenesis is different from other therapies out there.


What Makes Cold Thermogenesis Special

Do you want to know something amazing? 

Cold thermogenesis has some very special benefits. It's very hard if not impossible - in many instances - the get the same benefits in any other way.

So, in the same way, vitamin D supplements do not give you all the benefits of sunlight, you can also not supplement cold thermogenesis.

Let's look at these unique cold thermogenesis benefits.

First, while exercise in the gym just shrinks your fat cells, cold thermogenesis literally kills them [17; 42; 46; 69].

That means that weight loss through cold thermogenesis is different than weight loss realized through exercise or extreme dieting.

Simply put: cold kills your fat permanently.

Next, cold thermogenesis increases a process called "autophagy" [18; 19].

Autophagy allows you to replace bad mitochondria in your cells. Malfunctioning mitochondria need to be replaced, but cannot be replaced without autophagy.

When you get older, mitochondria increasingly malfunction. Autophagy during sleep allows you to replace these malfunctioning mitochondria.

Cold thermogenesis stimulates that autophagy process.

When your sleep quality is low - like so many people experience in modern society - that lowered sleep quality prevents you from using autophagy to its full extent.

How can cold help?

Nature normally emphasizes autophagy in cold environments. 

Cold thermogenesis thus indirectly allows you to renew your body's mitochondria, and thereby combats aging.

(Nerd section: in your maternally-derived (bacterial) mitochondrial DNA (mDNA) - which is different from the DNA you got from both your parents and found in the nucleus of your cells - develops increasing heteroplasmy rates over your lifetime. Mutations in the DNA of your mitochondria increase with aging, making mitochondria less energy efficient [83; 84; 85] Cold can partially offset that process.

Cold causes both fat loss and autophagy. Both fat loss and autophagy support more efficient sleep, which leads to improved overall health and better aging.

Are fat loss and autophagy all the benefits of cold thermogenesis?


Look at the list of more proven cold thermogenesis benefits. Cold thermogenesis:

  • improves your sleep quality [50]
  • lowers your hunger sensations [37]. 
  • decreases your inflammation levels [38; 40]. Inflammation lies at the basis of many modern diseases, such as heart disease.
  • may slow aging [39; 41; 65; 66]. While the effects of cold slowing the aging process has only been demonstrated in animal studies, but there are implications for humans as well.
  • regulates blood sugar, and lowers insulin resistance. In plain English, cold exposure decreases your chances of getting diabetes [47; 48; 49; 70].
  • changes immune system functioning [51; 52; 53; 54].
  • decreases pain [55; 56; 57; 58].
  • improves well-being [79].
  • builds muscle [67]
  • strengthens your bones [71]
  • even builds new mitochondria, so that you have more energy [72; 73; 74; 75]. Remember, mitochondria are the energy-producing "factories" in your cells. The more (working) mitochondria you have, the better your health and energy. 
  • betters stress tolerance [77; 78].

Besides these proven benefits, most people also report improved willpower, better hair and skin quality, and more confidence, 

(Nerd section: Cold thermogenesis even affects the fatty acids in your cells. When animals get closer to hibernation, they change the makeup of the fatty acids in their cells. Humans also change the fats in their cells before the wintertime [20].

During the spring and winter, their cells contain more saturated fatty acids and monounsaturated fatty acids. Examples of foods that are higher in these fatty acids are fats that come from land animals and plants. 

Foods that are higher in (healthy) polyunsaturated fatty acids, on the contrary, are mainly found in fish. These polyunsaturated fats are consumed in greater proportions in animals that hibernate. The fact that cold changes the fats in your cells, demonstrates again that diet is related to your environment (light and temperature).

You need cold exposure during the wintertime if you live at a location where the days get really short. You need cold to create dopamine, and to feel good during the wintertime.

When the days are very short at your location, sunlight can no longer make you feel good.

During short and dark days, the sun's ultraviolet light is not available to produce those good feelings.

Without applying cold to your body, your metabolism will stay in a "summer mode" 365 days a year. However, you're unable to feel great because there's no sunlight to create dopamine.

When the days are short, cold thus becomes important. If there are cold winters at your location, cold thermogenesis has massive benefits for your overall health.


Polar bears also spend the wintertime in a dark cold hole and lose most of their body fat over that time - mostly because of the cold. During spring, they emerge lean from the place they hibernate in.

You can have all these benefits with your own cold therapy sessions as well.

Let's first look at how you can create your own cold thermogenesis tub.


How To Create Your Own Cold Thermogenesis Tub

Why do I begin to talk about a cold thermogenesis tub? Why not mention cold showers, or another cold thermogenesis method: not wearing a jacket outside the house?

Well, a tub is cheap, and realizable for probably 50-60% of people on this planet.

Tubs are very efficient: skin contact with cold water lets you lose heat 30 times as fast as cold air.

I consider a tub optimal for doing cold thermogenesis.

You might have seen that I use a tub as well.

What's the story behind my tub use?

Since two years, I've been using that tub in the garden. That is a ~400 gallon (1.500 liter) tub.

The advantage of this tub is its price: The tub costs $350, and $30 to build a tap/drain into the tub. An additional cover costs $25.

That's about $400 total.

A drain/tap allows you to drain the tub without much effort on your part. After switching the tap for a second, the tub will take about 60 minutes to fully drain.

Tubs are very easy to find online. For example, you can get a stock tank (tub) here, and a drain here (affiliate).

Make sure to cover the tub's water when you're not using the tub.

I keep the water in my tub most of the time. I often use the tub first thing in the morning. When you use the tub during the morning, the water has cooled down during the night. That way, using a tub for cold thermogenesis is very efficient.

Additionally, because the water stays in the tub overnight, the temperature of the water inside the tub is colder during the wintertime than summertime.

Why choose a tub?

Well, a tub is very easy to use. You get out of bed, sit in the tub, get out, and start your day.

You do need to replace the water when necessary. During the summertime, the water needs to be replaced often. During the winter, almost never. 

(When it's freezing, algae do not grow here in the Netherlands. Algae are the main reason for water becoming polluted over time.)

You might be asking: "are there any disadvantages to this tub?"


The tub is made out of polyurethane. Polyurethane is probably a toxin [59; 60].

If your toxic load is high in your daily life, then I would avoid using polyurethane as a base material for a tub.

The toxic load refers to the total amount of toxins that your body has to process on a daily basis.

With a high toxin load, you could opt for another option, such as a "Cold Tub":

That cold tub is made of stainless steel. 

The cold tub can also be placed inside your home, and automatically cleans itself. The drawback is that the cold tub shown above sets you back thousands if not tens of thousands of dollars.

You can order a Cold Tub HERE

The Cold Tub has a huge advantage that you can 1) use the thing inside your home; 2) keep a steady water temperature 24-7, which massively saves time on your cold thermogenesis sessions; 3) no need to spend time cleaning.

Only buy that Cold Tub if you've got money to spare on the most premium option though...

But, that tub is the very best and I'll have one in my home in the future as well. 

If money is less of an issue for you, a stainless steel option is the best option.

A great benefit of these stainless steel cold tubs - which are usually placed inside your house - is that you can regulate the temperature very precisely.

Regulating the temperature allows you to better determine the intensity of your cold sessions.

Why have I chosen for a polyurethane tub anyway? Because my overall toxic load is pretty low:

  • I eat mostly organic
  • I do not put any toxins on my skin
  • I do not live in the city (so, no air pollution).
  • I spent tons of time in the sun and use additional infrared (which both detox).

If money allowed, I would certainly buy a stainless steel version!

There's a middle ground, however, between a polyurethane tub, and a stainless steel tub:

Old-fashioned metal tubs, made out of zinc, or steel, are an example (affiliate link).

You can also get a zinc tub for a low price at eBay, for example. 

The problem with metal tubs is that you cannot use them when it freezes outside: it's very dangerous to touch the metal with your skin. Alternatively, you might be able to buy a ceramic bathtub and place that tub outside your house. Ceramic tubs are also sold on eBay. 

In term of size, traditional bad tubs are a lot smaller than my polyurethane tub, and the higher-end stainless steel cold tubs. A bathtub holds about 100 gallons of water, while my tub holds about 400 gallons of water.

More water in a tub equals more skin exposure.

Bathtubs are sometimes too small for great cold thermogenesis sessions because your back and legs are not always exposed to the cold.

Moreover, wooden barrels are another good option:

wooden barrell

The problem with these barrels is that they are usually small (again). Good looking barrels are also expensive. The upside, however, is that barrels look very beautiful in the landscape.

Fortunately, most of the times, these barrels are free of toxins.

But what if you do not want to buy a tub or barrel outside your home? 

Well, a sub-optimal option would be to use the bathtub in your home.

The problem with indoor bathtubs, however, is that it's much harder to get the water inside the tub very cold. Tap water is usually hot compared to the water outside your home.

The alternative, adding ice cubes every time you enter your bathtub, becomes expensive over time. Additionally, bathtubs in your house also take a lot of time to fill. 

Filling up your bathtub takes time when you want to do a couple of cold thermogenesis sessions each day.

An in-house bathtub would thus not be my first option for doing cold thermogenesis.

That's why a tub outside the home is more efficient. A tub outside the home might not need to be refilled every time you use it, especially during freezing winters.

(to be honest: you do need an axe during the winter, to "break the ice")

Besides barrels, is there another to do cold thermogenesis?

Yes. I've kept the best option for last.

This option is even better than having a stainless steel cold tub in your house. 


Are you ready? Just swim in a lake! Yes. It's that simple.

Doing cold thermogenesis in a lake is your best option because the lake is grounded. 

Grounding might be able to reduce inflammation, could lower stress, and give you more energy.

(Nerd section: medical (biochemical) evidence on grounding is potentially biased, because of conflicts of interest [86; 87]. From the earlier physics perspective, however, grounding should be able to remove excess protons from the human body, so that the human body can become more negatively charged. From a physics perspective, one should be able to deduce that grounding ought to work.)

But let's say you can neither do cold thermogenesis in a tub, nor in a barrel, nor in nature. 

Using A Freezer:

Since a few years, many people also have very good results by using a freezer that is up to a meter high. Such a freezer allows you to keep water temperatures steady at 2 or 4 degrees Celsius so that you're always ready for the next cold session.

Cleaning the freezer is a bit more difficult though but is generally doable as most freezers naturally have a drain.

The benefit of using a freezer is that the device is always at the right temperature.

If you don't like cleaning, then your next best options are cold showers and face dunks.


Cold Showers And Face Dunks: The Universal Cold Thermogenesis Applications

Let's first talk about cold showers.

If you cannot get access to a tub, barrel or lake, then cold showers are a great way to integrate cold thermogenesis into your life.

It's very simple: you just need a shower. How should you start with cold showers?

To begin, end your normal shower session with a few seconds of extreme cold.

Then build up the time you expose your body to the cold from there. Add more and more cold, and remove more of the warmer showering time.

In the beginning, do not expose your head to the cold water. You might faint or lose your coordination when your head becomes too cold too soon.

The goal is to build up your cold exposure gradually. Over time, you should be able to say within a cold shower for a couple of minutes. Finally, you will be able to handle very long sessions.

If you do not think that you can handle a few seconds of a cold shower, then there's another cold thermogenesis option for you: face dunks.

How to do face dunks?

Face dunks are simple:

  1. Get a large bowl of cold water
  2. Hold your breath
  3. Immerse your face into that bowl of cold water
  4. When the water gets very cold, or you can no longer hold your breath, remove your face from the water.
  5. Begin slowly at first


Literally everybody can do it:

They can. So can you!

Immersing your face into water actually activates what is called the "mammalian dive reflex".

The mammalian dive reflex is a response that is automatically activated in humans (and other mammals) when their face enters the water [76].

And yes, before you ask, face dunks may hurt in the beginning!

But you will adapt soon. After some time, people learn to hold their breath for several minutes.


The mammalian dive reflex actually lowers your need for oxygen. You simply immerse your head into water and activate that reflex. 

My general point is this: you can overcome your fear of cold showers with face dunks. And you can overcome your fear of taking cold baths or going to the lake, with cold showers.

You simply increase your cold exposure over time.

So, there's an intensity progression in cold thermogenesis applications:

  1. face dunks
  2. cold showers
  3. cold baths
  4. ice baths

Next, let's see how exactly to determine the intensity.

Do you want even more cold thermogenesis methods? Receive a PDF with 3 additional methods:



Cold Thermogenesis Sessions: Determining The Right Intensity

Always remember: always first consult your physician before getting started with cold thermogenesis.

Even if you have a disease, cold can be very beneficial. But I cannot (and will not) be responsible for people using this technique. The responsibility lies fully with you.

You see, cold thermogenesis can be misused.

To avoid misuse, you need the right intensity of cold exposure. Without the right intensity, cold thermogenesis can have side effects.

What can go wrong?

Well, when you overdo cold thermogenesis. With overuse, the best-case scenario is that your body takes a lot of time to recover. The worst-case scenario is that you permanently damage your body (or even die)!

Some types of cold thermogenesis are even inherently dangerous if you're not experienced.

Ice baths, or swimming in ice, are examples of more "dangerous" cold thermogenesis methods.

Ice baths and ice swimming will cause your body's temperature to cool down very quickly. When you cool down very quickly, it becomes harder to determine the intensity of your cold thermogenesis sessions. Phrased differently, it's very easy to overshoot on the intensity with ice baths and ice swimming.

Danger, of course, does depend on the person who uses the method.

Therefore, the first few times you use ice baths or swim in ice, there should be a person with you. That person can guarantee your safety.

All these cautionary tales, however, still do not answer the main question of this section:

How intense should my cold thermogenesis sessions be?

The best way to determine your cold thermogenesis sessions is to measure your skin temperature. I measure my skin temperature with an infrared thermometer:

infrared thermometer for measuring temperature


Simply point the thermometer at the area you want to measure and press the button. You can buy one here.

An infrared thermometer only costs about $20 dollars and measures the temperature of your skin in less than a second.

Why use the infrared thermometer?

Well, the goal is to have your skin temperature never fall below 10 degrees Celsius (50F).

You need to measure your skin to know its temperature,

With the 10 degrees Celsius temperature, your cold thermogenesis should never be too intense (assuming that you're in good health).

If you have health problems, the 10 degrees Celsius guideline may still be valid. However, these people need to monitor more closely how they respond to cold thermogenesis after a session.

If a cold session makes you stay cold for 2 hours, then the session was too intense. If you take long to recuperate, slow down next time.

Are there other ways to determine the intensity of a session?


If you do not have an infrared skin thermometer, how you feel after a session determines the intensity of a next session.

Let me give you an example.

Let's say I do a cold shower, and I keep feeling cold afterward. If that cold feeling lasts for 3-5 minutes, the session probably had the right intensity. However, if the cold feeling lasts for an hour or two hours, then the session was probably too intense. 

There are two ways to reduce the cold thermogenesis session intensity. First, you can lower the temperature next time. Secondly, you can make your sessions shorter.

Even though you can develop an intuition regarding the intensity of your sessions, I always recommend an infrared skin thermometer.

I did not use an infrared thermometer during my first year of cold thermogenesis. However, I can determine the intensity of my cold thermogenesis sessions much better with an infrared thermometer.

But let's return to the story...

What else do you need to consider before moving into the cold?

  1. If you're a beginner, make sure you've eaten before your sessions.
  2. If you're older or have a disease, make sure that you increase your exposure to cold very slowly. Older people have less brown fat, which helps convert regular body fat into energy during cold thermogenesis.
  3. If you're beginning with cold baths, you may want to start with keeping your hands and feet out of the water. Hand and feet usually give in first. Alternatively, you can buy neoprene gloves and socks to prevent your hands and feet from giving up before the rest of your body does (affiliate links).
  4. Start slow. See how you recover from a session. Only after you've concluded that you can recover well from a session, increase the intensity.

When should you do cold thermogenesis sessions?

You can do these sessions any time you wish.

Do not use cold thermogenesis in the few hours after exercise though. 

Using cold after exercise can prevent your body from gaining benefits from the workout.

Also, this advice may be obvious: never start out by doing several cold thermogenesis sessions each day. For optimal health, you will not need that many sessions.

Just a few sessions each week will already give you massive health benefits. 

Should You Use Cold If You've Got A Chronic Condition?

If you've got a chronic health condition, I no longer believe that cold exposure is beneficial to you. I also think cold exposure should not be prioritized. The reason is simple: with a condition, taking care of nutritional deficiencies (which inadvertently exist) and making sure you're sleeping well should be of utmost importance. The same is true for removing stressors from your life (either psychological or stressors in the environment).

So if you've got fibromyalgia, diabetes, Lyme, or another condition, steer clear from the cold. If you're in good general health, however, then you can slowly start to push your limits. Why? Simple: in a diseased state, energy should not be allocated towards keeping you hot but towards healing instead!

There you have it. The cold thermogenesis guide.


Conclusion: Start With Low-Intensity Face Dunks And Cold Showers

After three years, cold thermogenesis is still part of my daily routine. 

I've had days when I did 3-4 ice bath sessions in one day. As long as the intensity is not too high, you can recover very quickly.

The health benefits of cold thermogenesis will keep on accumulating, the more sessions you do. Such frequent sessions do presuppose that you are healthy though.

Why should cold thermogenesis be part of your life?

Well, the answer is simple: cold thermogenesis makes your mitochondria more efficient so that your body can produce more energy.

When you integrate cold thermogenesis into your life efficiently, the benefits will keep on increasing and increasing over time. A tub outside your house the simplest way to integrate cold thermogenesis into your life.

Another option would be to use the lake or ocean.

Over time, your sleep, energy, well-being, immune function, strength, endurance, and more, will all improve.

That's why winter is coming.

At least, I hope so...

Also make sure to read my blog post on cold water immersion, which digs into the topic from another perspective.

Lastly, enjoy this quick overview:

And great luck with your cold sessions!

Oh yeah, one last thing:


Frequently Asked Questions:

Should I still expose myself to the cold during summertime?

Yes, cold thermogenesis will still make your mitochondria more efficient. More efficient mitochondria mean that your body produces more energy.

However, your body will not enter "winter mode", because of the presence of greater amounts of ultraviolet light in your environment.

Only for some people who's mitochondria are almost exclusively African based - in terms of their mitochondrial DNA - should it be advised not to overdo cold thermogenesis. Why? The mitochondria of these people are more efficient, meaning that less energy is burnt as heat, which in turn means that they have more trouble heating themselves during cold thermogenesis.

European people, for example, have less efficient mitochondria, meaning that more energy is burnt as heat, and less energy available for other processes.

Do I need to eat differently in the wintertime?


Temperature and diet are strongly related to each other [32; 33].

If the days are very short at your location, that means that not a lot of ultraviolet light is present at that time.

And if ultraviolet light is not present, and the days are short, that means that not many carbohydrates grow at your location.

When there not many carbohydrates grow at your location, that means that your body switches to a more ketogenic diet.

Why does it take three hours to warm up after cold thermogenesis?

Your session was too intense.

You probably did "deep" cold thermogenesis, which is more intense. Deep cold thermogenesis is not treated in this article because safety cannot be guaranteed.

Deep cold thermogenesis is akin to heavy resistance exercise. Regular cold thermogenesis is more like "movement", which you should be able to do without overexerting yourself.

To avoid deep cold thermogenesis, decrease the temperature of the water, or the length of your cold thermogenesis session.

I'm an athlete. How should I use cold?

Schedule your sessions away from your regular training sessions.

Do not use cold thermogenesis after your regular training session, as doing so can impede the training adaptations of your regular session.

The best is to keep the sessions apart. I, personally, often do cold thermogenesis sessions in the morning, and strength training sessions in the afternoon.

Will cold thermogenesis give me a cold?


Common colds are actually caused by viruses. Viruses are transmitter better in colder temperatures. So, because the transmission of viruses is greater in colder temperatures, people get colds more often during the fall and wintertime.


This is a post by Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - Cum Laude), and Clinical Health Science (MS), and is currently the chief science writer at 

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