I grew up in Minnesota, in a suburb of the Twin Cities called Lakeville, and it was wonderful. I was close to the Twin Cities but just far away enough for an almost rural life. My favorite times of the year were Spring, when the snows had melted and the plants were starting to grow and bud, and Fall, when the leaves turned color and the brisk winds were a pleasant relief from the Summer heat and humidity.

But other than those two seasons of the year, the weather was harsh.

Summer was very hot and humid. We would go to the malls and movie theaters just to get into some air conditioning. Sometimes the heat was so oppressive that sleeping at night was difficult. The winter was incredibly cold. We used to be thankful for snow, because that would mean that the temperature would be a bit warmer. It actually got too cold to snow, and people used to say that we had nine months of winter and three months of bad skiing.

One of the truly wonderful things about Minnesota is the people. They tend to be friendly and polite, and they help each other. If a car has difficulty on a snowy road, many people will stop their cars and offer help. Everyone knows that the next time it could be them.

After I graduated from the University of Minnesota and completed my residency, I got a job offer in Florida. I lasted all of a year. Although there are wonderful people there, I felt trapped—there were too many people. And the weather was almost the reverse of Minnesota: hot and humid for most of the year. I wanted to run away. I found I actually missed the cold of my home. I guess I had become accustomed to it.

So when a job opened in a small, cold place, I took it. It is a little town I'll call "Tallman" in Alaska. Tallman is very rural and small. In the winter, snowmobiles are the most common form of transportation for getting around town. That's when I started worrying.

In Minnesota, the roads I frequented were almost always cleared of snow in the winter, and if you got in trouble, there were other people driving by. In Tallman, there were neither cleared winter roads nor frequent drivers. If your snowmobile broke down and you were stranded outside the town proper, you could be in a lot of trouble. I decided I needed to do something by way of preparation.

Even though our town is small and out of the way (in the winter, flying in is the only way to get here), we don't lack for necessities of modern life, including access to the Internet. I did searches through various areas and found special heaters; small, lightweight blankets that were supposed to keep you warm; and other gadgets. I felt uncomfortable with all of them.

In my Web searching, I found a reference to something called tumo. The websites I visited didn't say much more than that it was a Tibetan technique to keep warm. It claimed that tumo could keep you warm "in spite of snow, freezing winds, and ice." It worked by a meditation technique that would send a "mystic heat" through veins, arteries, and nerve channels. This process, they claimed, would keep you warm even during freezing conditions. But they didn't say how to do it.

For the past several years, I have been a doctor, and my interests have been firmly in the scientific world. The Internet is filled with some rather bizarre medical claims, and I take most of them with more than a grain of salt. Some of my patients come in with these supposed cures, for everything from hair loss to benign prostate disease. I always ask for the scientific proof. Sometimes what you read on the Internet is accurate. Sometimes it is exaggerated. And sometimes it is just wrong.

Needless to say, the idea of tumo sounded absurd to me. But whether it worked or not would be easy to prove. All I had to do was try it. But before I could do so, I had to learn it, and I was finding dead ends everywhere.

Finally, I saw a review of a recently-published book that claimed to give the entire process for learning tumo. I clicked on the "to buy this book" icon and purchased the book over the Internet. Soon I had a copy of Occult Tibet by J. H. Brennan.

Chapter six exclusively teaches the technique of tumo. Brennan says that in Tibet the training would take "three years, three months, and three days," (p. 61), and this disappointed me. But he quickly follows by saying that this "clearly has symbolic association." I was relieved to discover that it might take a much shorter time. Besides, the author adds that "the various steps of the exercise have benefits in their own right." I was ready to start.

There are three stages to learning tumo, each having several parts. The first stage consists of preliminary exercises. The first exercise shocked me and almost turned me off to the entire practice! So don't turn away after reading the technique, be sure to read the explanation afterward.

"[V]isualize yourself as the naked, virginal, sixteen-year-old Vajra-Yogini, a Tantric divinity who personifies spiritual energy. This goddess has luminous ruby-red skin and a visible third eye in the middle of her forehead. In her right hand she holds a gleaming, curved knife high above her heard to cut off completely all intrusive thought processes. In her left hand she holds a blood-filled human skull against her breast. On the head of the goddess is a tiara made from five dried human skulls, while around her neck is a necklace of fifty human heads dripping blood. She wears armbands, wristbands, and anklets, but her only other item of adornment is a Mirror of Karma breastplate held in place by double strings of beads made from human bones that circle her waist and pass over her shoulders. There is a long staff in the crook of her left arm, and a flame-like aura around her whole form. The goddess is dancing with her right leg bent and the foot lifted up while her left foot tramples a prostate human." (p. 62)

Yuck!

When I read this repulsive description, I figured this was too bizarre for me. But I read on to discover that "even the worst of the horrors has symbolic significance. The necklace of human heads, for example, should be seen as representing separation from the wheel of birth, death, and rebirth that locks humanity into the world of illusion." (p. 62) Understanding that this was all symbolic made me feel a bit better, so I decided to continue.

The book explains that this is just the outer form of the goddess and internally you should imagine yourself empty, "like a silken tent or shaped balloon." (p. 62) Visualizations had always been easy for me. When I was studying medicine, I used visualizations of myself easily and successfully passing tests to relieve exam anxiety. This was a bit different, however, because I was supposed to have two images in my mind at the same time, the external image of the goddess figure and the internal emptiness. It took me a few days to master this.

Next, per the instructions in the book, I increased the size of the goddess image, larger and larger, until it was as big as a house, a hill, and so on until it encompassed the entire universe. I stayed with that visualization for a time. It was, as they say, a real "mind-rush." Then I did just the opposite, shrinking the visualization down until it was the size of a tiny seed and then to microscopic levels.

The next exercise is to visualize the Vagra-Yogini the same size as me, and then concentrate on visualizing an energy channel down the middle of my body. "It should be seen as straight, hollow, about the size of an arrow-shaft, and a bright, almost luminous red." (p. 63). Again, per the instructions in the book, once I had this down I expanded the channel until it was the size of a "walking staff, then a pillar, a house, a hill, and finally large enough to contain the whole of the universe." (p. 63) At this stage the channel, of course, pervades the entire body, not just the center of it.

Then I was to visualize the channel getting smaller until it was about one-hundredth the thickness of a hair. All of this was fairly easy for me to do, and within a week, I was pretty good at it.

The third exercise begins with sitting in the famous cross-legged lotus pose found in Hatha yoga. I had studied yoga for a while, and quite frankly, I could never do the lotus pose. Luckily, the teacher I had gave me a solution: "Do the best you can. Alter the pose to fit your needs." I found that if I sat on the edge of a cushion I could modify the pose a bit, be comfortable, and get the desired effects of the pose. Brennan mentions some alternatives, too.

Sitting in this position (with the right leg on top), you put your hands in your lap, palms up, with the forefinger, thumb and pinky extended. The spine should be straight, chin down, tongue against the roof of the mouth, and the eyes fixed on the tip of the nose.

Take three deep breaths and exhale completely. Then inhale as much as possible and hold the breath as long as possible without straining. "As you breathe out, imagine that five-color rays emerge from every pore of your body to fill the entire world. The colors, which equate to the elements, are blue, green, red, white, and yellow—symbolizing respectively ether [spirit], air, water, and earth. On the in-breath, imagine these rays returning through the pores to fill your body with multicolored light. Repeat the exercise seven times." (p. 64–65) I found this part of the exercise to be very stimulating; leaving me feeling balanced and energized.

The exercise continues with sound, visualizing the concept of the five colors being part of the syllable hum (I guess that is the Tibetan equivalent of the Hindu Om). On the exhalation I would visualize the world being filled with the colored hum. On inhaling I would feel the sound and colors enter and fill my body. This, too, was repeated seven times.

The next part of the exercise was to imagine that each time I exhaled, the colored hum sound changed to mustard seed-sized versions of fierce, angry, and menacing deities. Such deities are common in Tibet. On the exhale they were to fill the world, while on the inhale they were to fill me. This was repeated seven times. Believe me, the feeling of all these little creatures, even though they were only visualized, was quite...interesting, to say the least.

The next part of this step is, according to Brennan, a "critical stage in the exercise. You are required to imagine that every pore of your body is inhabited by one of these tiny deities with his face turned outward. The result of this visualization, when performed correctly, is that you see yourself as having grown a second protective skin composed of fierce and angry deities, which functions rather like a suit of mail armor." (p. 66)

For two weeks, I practiced this. Although I could sense the deities, I didn't have a feeling of them being armor. Then, at the end of two weeks, I had a dream in which I was having a battle against giant monsters. Although I battled valiantly, I realized I would lose. "Somebody help me!" I cried out. I immediately heard a tittering sound. Looking around I saw tens of thousands of tiny, angry, Tibetan gods. "Oh great," I thought, "a lot of good they're going to be." Instead of fighting the monsters, they started jumping on top of each other until they formed a wall between the monsters and me. "Hey, this looks like it might work," I said. Then the wall of deities moved toward me, and with a leap, surrounded me like a second skin. At first I thought I wouldn't be able to breathe, but I quickly realized that their protective cover didn't harm me in any way. Better, it prevented me from being harmed by the monsters, although my sword could cut through the beasts.

When I awoke, my first thought was that I had, indeed, been successful in getting the deities to be an armor-like second skin. But then I wondered, "What were the monsters?" I thought about it for a day before I realized that I was feeling very happy, content, and peaceful. In my dream I had defeated my own fears, phobias, insecurities, and other negative qualities. It didn't mean I had won the "war" with them, but I had won a battle. That knowledge made me feel great! Even if this tumo didn't work, I'd already learned a powerful technique for personal development.

There are two other exercises in this stage, but I'm not sure that they are necessary for this overview, so I'll leave it for you to study them and decide for yourself.

In the second section Brennan goes into actual techniques for learning how to generate what he calls psychic heat. It begins with breath control known as Nine Bellows Blowings:

"Close off your left nostril with your forefinger so that you are breathing only through the right nostril.
"Turn your head slowly from right to left while inhaling and exhaling three times through the right nostril.
"Now close off your right nostril and inhale/exhale three times while moving your head slowly from left to right.
"Finally, with your head steady and looking straight ahead, inhale/exhale three times through both nostrils." (p. 69)

This cycle is repeated three times. The first set has you breathe very, very gently. The second is stronger. With the third you inhale and exhale very completely, using the abdominal muscles to help push out all of the air. For me, this was easy to do. It only took a short time to get the feeling that I was doing it right.

The next step is called Four Combined Breathing. Bend your neck over and silently and deeply (let your chest bulge out) breathe in through both nostrils as if the breath was coming from about a foot-and-a-half in front of you. When this inhalation is hard to maintain, take several short breaths to equalize the pressure in both lungs.

When you are totally filled with air, begin to exhale gently, then with greater force, then gently again, all on a single breath. This is called "shooting the breath forth like an arrow." (p. 70) Indeed, that name described what the sensation felt like.

The above two techniques are known as Calm Breathing. The next technique is called Violent Breathing. It has five exercises that are described briefly. They all involve realizing that with every breath,energy is coming into your body. More importantly, the "final technique of the sequence seeks to mingle the internalized life force with the great reservoir of cosmic energy all around you. This is referred to as the Art of Relaxing the Breathing, a name which suggests the process involves an out-breath." (p. 72) I took this to mean that I should visualize energy coming in with each breath, combining with my inner energy in my lungs and expanded body (from the first stage), and sent out on the exhalation. Practice of an hour a day for a week made this very powerful, and I felt filled with power, but not "antsy." My power gave me peace of mind.

The next part of this stage involves visualizations. Again, you visualize the Vajra-Yogini, but "instead of imagining yourself as this deity, you should create an image of the goddess standing at normal human size before you. This image becomes your contact point with the universal energy and part of a visualized 'generator' that will produce the psychic heat." (p. 72–73) When I read that this was where things will start, I got really excited. I had this visualization down pat within two days.

The next visualization, as before, deals with the energy channel. But rather than just the one main channel, there are now three. The center one is hollow, red, transparent, and bright. Two more go on either side of this central tube, gently curving to the center, crossing each other at the central point and continuing in this way back and fourth. This is just like the image of the caduceus, the wand that was the symbol of medicine, my profession.

At each crossing point through the center channel, there is a chakra, or power center. There are four major chakras (this is different from the popular pictures I've seen, but most of those deal with the Hindu chakras, so I made up my mind to try this out.)

The next part is difficult to explain in a brief article like this; you'll have to get a copy of Occult Tibet for yourself. The basic idea is that you take two letters of the Tibetan alphabet (for those familiar with it, they are the letter ham and half of the vowel A) and visualize them in certain ways while working with the breath. It's not difficult, just complex to describe. As you do this work, the letters change to flickering, spinning fires. At the tip of the Ham is a drop of pearlescent "moon fluid," which overflows the crown chakra above the head and then flows over the chakras at the throat, heart, and navel, and finally the entire body.

"The overall sequence of 108 breath cycles constitutes a single tumo course. To become proficient, you will need to repeat six courses over each twenty-four-hour period in the early stage of your training." (p. 75–76) I practiced this until I could sense that I had an increased amount of the universal life force charging me. The book advises to cut the number of courses to four after that increase occurs.

The third stage is triggering tumo. Brennan reveals that there are three ways to trigger the heat of tumo. Once you have practiced and can perform all of the exercises already given, the simplest means of triggering the heat is through deep, diaphragmatic breathing. The third method he gives involves visualizing yourself with all of the above images and with suns blazing in the palms and soles. Bring the palms together and then the soles so the suns meet, then rub the palms and feet against one another. "[F]ire will flare up to strike the sun below the navel, then the [Ham] symbol, and go on to permeate your whole body." There's a bit more to it revealed in the book, but this is the basic idea.

However, it was the second method that most interested me: "While seated in a simple cross-legged position, grasp the underneath of your thighs with your hands. Use your stomach and abdominal muscles to circle the belly area three times to the right and three times to the left while keeping the torso still. (You can prepare for this by first moving the muscles left and right, then gradually building up to a circular movement.) Churn the stomach vigorously by rippling the muscles from top to bottom, then shake your body like a dog that has just come out of the water. While you are doing so, raise yourself a little on your crossed legs, then drop back again onto your cushion, in effect bouncing a little off the floor. Repeat this whole exercise three times, ending with a more vigorous bounce." (p. 76)

According to Brennan, if you perform twenty-one vigorous bounces while doing the visualization for a week, "you will be able to endure almost any degree of cold" (p. 77) while wearing only a thin cotton robe. This was what I wanted! I practiced daily for a couple of weeks. Then I settled down to practicing only twice a week.

By this time, Spring had arrived, and the snows were melting. I was giving myself several months of practice before relying on tumo for my safety. I could swear that I was generating heat, but was it my imagination or was it real? Then there was a surprise cold spell and a late snow. I decided to test what I had learned.

I drove out to the side of a large hill not far from Tallman. By the afternoon, the sun was behind one side of the hill, and the dark side was not only covered with eight inches of snow, but was in the shade. The cold had gotten worse, so it wasn't going to snow any more that afternoon or night. Using a snow shovel, I quickly made a six-foot-high pile of snow. Then I packed it down firmly and piled on more snow. I repeated this until I had a six-foot-tall mound of hard-packed snow. It was a little after 4:00 when I climbed to the top of the pile and stripped off my parka and outer clothes, leaving only my underwear. I sat down, cross-legged, making a crunching sound as the snow compressed under me. Within seconds, my teeth were chattering and my skin started to feel numb. I closed my eyes to focus on what I was going to do and started using the second method to trigger the tumo heat. My stomach churned side to side and top to bottom. I bounced once. I did the visualization.

I repeated this, making the bounce more vigorous and gave more effort to the visualization, trying to make it even stronger than before. On the third round, everything seemed to flow. I got an eerie feeling that time was changing. I think the visualization lasted a long time. After the fourth round, I noticed that my teeth were not chattering and my body did not feel numb at all. I was feeling rather comfortable. Was this really working?

By the seventh bounce and visualization, I was feeling peaceful and warm. Actually, I was feeling very warm. I realized that there was nothing in the book that said how long this effect would last. I just sat there with my eyes closed, relaxing, feeling comfortable.

And then I noticed something odd. It was a sensation I had experienced innumerable times before, but it was odd right now. There was a slightly itching sensation at the tip of my nose. It was a drop of sweat! I was perspiring. This really works. I wiped the sweat from my nose, but my realization had broken the state I was in. I opened my eyes.

It was dark in front of me. Every where I looked it was dark. I was terrified. What had happened? I looked up and saw stars. The heat from my body had been so warm and so long lasting that it had formed a hole four-feet deep in the snow! As I clambered out of the hole, I realized how desperately cold it was and struggled back into my icy clothes. There was a propane heater on my snowmobile and I started it up. In a few minutes I was warm without the need for tumo. Now that I had this technique and knew that it worked, I wouldn't have to rely on having a supply of propane for an unknown amount of time. I could be safe and warm and not worry. But for how long?

I thought about the stars and realized that it was night. I checked the watch I had left on the snowmobile. It read 10:37 pm. I had been safe, warm, and comfortable for over six hours! This was absolutely astounding and amazing.

Having lived in areas that get very cold for most of my life, I can tell you that one way to survive the cold is to build a small snow building like a cave or igloo. Sheltered from the wind and warmed by your body heat, it may be your only way to survive without dying from hypothermia. So it could be that the pit-like hole in the snow was what kept me warm and safe that afternoon and evening. At least, that's what the skeptical side of me would say.

But who or what made the hole? I didn't dig it. In fact, I made sure that the snow was firm and hard packed so I couldn't just sink down. Even if you accept the idea that the pit I sank into kept me warm, the only conclusion I can make is that through tumo, as taught in Occult Tibet, I was able to create enough heat to create that pit in the snow.

I look forward to the mild summer weather ahead, but I intend to keep up my practice. Winter will come again and I feel very safe. Perhaps I'll melt some new holes in the snow in a few months.