The Practice of Fierce Inner Heat

Judith Simmer-Brown on tummo, one of the most famous esoteric practices of Tibetan Vajrayana and the Six Dharmas. What is it, what are its benefits, and what role does it play in our journey to enlightenment?

By Judith Simmer-Brown

“Milarepa,” Tibet, 1700–1799, Kagyu Lineage, 26.50×18, Ground Mineral Pigment on Cotton, Rubin Museum of Art, Acc. # P1999.31.3, Item no. 0921

One of the most renowned yogis in Tibetan history, Milarepa (1040–1113), transformed his negative karma through deep practice on retreat, in time becoming a great inspiration for practitioners, who still sing his many “songs of realization” describing his path to realization and joy. His name derives from his clan name, “Mila,” with “repa” referring to the simple cotton robe that he wore, which marked him as an accomplished practitioner of tummo (Sanskrit: chandali), the practice of yogically generated “fierce inner heat.”

Milarepa received this practice from his root guru, Marpa Lotsawa (1012–1097), who brought tummo from India on one of his three pilgrimage journeys. Following the command of his guru and motivated by deep remorse for his earlier practice of black magic (which is said to have caused the deaths of thirty-five relatives), Milarepa committed his life to solitary retreat in the icy cold wilds of the Tibetan plateau. Eventually, he was able to abide happily with only a white cotton robe because of the excellence of his tummo practice. With this foundation, over many years, Milarepa mastered his own mind and his past karma, becoming fully realized.

What is tummo, and why was it so important to Milarepa’s practice? One of the classic yogic practices of the Six Dharmas (Naro Chodruk) promulgated by the great Indian siddha Naropa (1016–1111), tummo is considered the foundation of all the others. It is a meditation practice that powerfully synchronizes mind and body through mastery of subtle body channels through specific breathing conjoined with specified visualizations. Naropa called tummo “the pillar of the path” that forms the foundation for all the other Six Dharmas practices because of its incomparable power to directly awaken our inherent nonconceptual wisdom (Tibetan: mirtogpa; Sanskrit: nirvikalpa) residing in the body. Tummo “destroys the attitude of dualistic thinking,” which, according to Chögyam Trungpa Rinpoche, is the source of all our suffering. Tummo employs our core somatic life-force heat in service of the spiritual path, directly introducing us to embodied nonconceptual wisdom, greatly accelerating the journey to realization. Milarepa said, in The Three Cycles of Illumination:

The ultimate essence abides primordially
within corporeal beings, all of them.
Thus sentient beings are the cause of buddhahood….
Like clouds in the sky,
thoughts are adventitious.
They are not stopped by forceful means—
they cease naturally. 

The power of tummo as foundation distinguishes all the Six Dharmas from conventional meditation. Milarepa chided his student Gampopa’s ordinary concentration meditation, saying that tummo practice surpassed it by far: “I don’t know why you are so proud of it. You cannot get olive oil by squeezing sand. My inner fire meditation is incomparable.” The modern teacher Lama Thubten Yeshe (1935–1984) likened tummo to shooting a rocket along a completely straight path, highlighting what is truly essential, while even well-honed concentration practice is merely like dreaming. 

Tummo practice originated in the tantric communities of medieval India, associated with the wild goddess Chandali, who is depicted as wrathfully erotic, and carrying a pot of fire. Some scholars have erroneously conflated tummo practice with the Hindu kundalini practices presided over by the goddess of the same name, but in Tibetan Buddhist practice, “chandali” is not referencing the goddess per se, but the actual experience of yogic heat, generated at or below the navel, that produces intense bliss. Tummo is associated with the mother energy of the pelvic bowl of the subtle body and with the esoteric traditions of the embodied dakini.

A mahasiddha in tummo stove posture. Mural (detail), Lukhang Temple, Lhasa, Tibet. ca.1700. | Photo by Ian A. Baker.
Naropa called tummo “the pillar of the path” that forms the foundation for all the other Six Dharmas practices because of its incomparable power to directly awaken our inherent nonconceptual wisdom residing in the body.

Marpa received this practice from his Indian guru Naropa, who had himself received it from his guru Tilopa (988–1069), the earliest siddha of the Kagyu lineage. It is said that Tilopa learned tummo from various gurus in India and adapted it in his practice. Milarepa wrote in The Three Cycles of Illumination that after receiving the practice from Marpa, he “enthusiastically took up these instructions and practiced them with perseverance.” As a result, he experienced chandali blazing in his body, remarking, “I was warm with only cotton clothing—and luminosity shone in my mind.”

Tummo is a practice from the Vajrayana, the “vehicle of skillful means” that emphasizes expeditious methods of practice (as opposed to the view itself) that quickly bring results. It is also considered a formless completion stage (Tibetan: dzogrim) practice “with elaborations,” meaning that it builds upon deity (yidam) visualization practice with an emphasis on the subtle, energetic dimensions. Preparation for tummo practice requires that the practitioner be well established in meditation and steeped in the sadhana practices of a deity as bestowed by the guru. Deity yoga practice powerfully transforms our experience by loosening the hold of conceptual elaborations and emotional drama so that we can glimpse freedom of bias. The yogic practices of the Six Dharmas expedite the success of sadhana practice, allowing us greater clarity, bliss, and freedom in deity yoga. 

Tummo relies upon the subtle body, traditionally called the “body made of mind” (manomaya kaya in Sanskrit). The subtle body is not really a body; it is much more like an embodied mind animating the gross body in a pivotal way that influences our direct experience. Its fluidity is seen in the way we cling to concepts and emotions and the way we can let them go through meditation practice. It also enlivens embodied experience, moving the gross body with a mere thought or intention. 

The subtle body manifests as a supple network of energy channels (tsa, nadi) of pathways radiating from vertical channels in the spinal area, interlinking the entire body-mind. Winds or subtle breath (lung, prana) move through these channels, invigorating the entire body. This movement happens naturally, but meditation practice can guide its movement, clearing away obstacles and knots. The movement of the subtle winds allows sense perceptions to function, emotions to be felt, and speech to be uttered. The proper circulation of the subtle winds ensures excellent health, emotional balance, and mental clarity. Conversely, the blockage of these winds exacerbates emotional eruptions, health problems, and general confusion.

Although the mind and subtle winds are different in function, they should be considered inseparable. In yogic practice, it is crucial that the mind consciousness be trained to follow, even ride, the movement of the breath and winds in meditation practice. The traditional metaphor likens the breath to a horse, which, once recognized, can be ridden by the natural, undisturbed mind (Tibetan: nyugme-sem) in meditation practice. Because of the intimate connection between the literal breath of our life and the movement of inner winds, the metaphor of the horse applies to both conventional meditation and subtle body yoga. When the mind rides the breath with careful attention, the turbulence of the unsettled mind is dispelled and awareness may eventually dawn in the mind as luminous clarity. This is the essence of calm-abiding meditation. 

When insight dawns, its power may generate a dynamic point of energized awakened awareness (thigle; bindu) in a form like liquid drops within the subtle body. This concentrated energy, also called bodhicitta, gathers at focal wheels along the central channel in the spinal area. If the mind is deeply tamed and trained, and is focused with altruistic motivation, it is possible to move the thigle points through the channels riding the winds, exponentially enhancing the efficacy of the practice.


Kagyu master Tashi Namgyal (1513–1587) distinguished three stages of preparation for tummo practice.

First, we start with the visualized empty form of the yidam deity with all the vivid outer features and ornaments as in sadhana practice, focusing on the hollow body of the yidam whose shape and form is insubstantial. Then we deeply acknowledge that we are none other than this vivid form, appearing but empty, manifesting in a world of empty forms. This requires surrender of the ego to the guru’s lineage, to the power of the practice, and to the inherent openness of nonconceptual wisdom.

Second, we visualize the full splendor of the subtle body, empty and radiant, within our own body as the deity. We visualize the central channel (uma, avadhuti) with the two flanking channels (kyangma, lalana and roma, rasana), left and right, while maintaining the explicit yogic posture of seven points, sitting upright with tucked chin, straight spine, crossed legs, and closed lower pelvic gate. This visualization may begin as a kind of instructive wishful thinking, but over time, we awaken to the dynamic quality of the subtle body that enlivens all embodied experience. The chakra wheel points along the central channel, four of them in all, are also visualized. We especially emphasize the cool masculine energy of the crown chakra and the fiery feminine energy of the navel chakra, each with their distinctive seed syllables.

Third, we practice “vase breathing” (lung bumpachen, kumbhaka), a subtle energized somatic breathing that retains the breath in a particular way in the inflated lower belly. It is essential to receive instructions from one’s guru on this practice, as it is easy to be too coarse and to cause a reactive response or too lax to bring awakened power to the belly. Because the breath is so essential in awakening our inherent nonconceptuality, this practice is subtle, powerful, and transformative. Mastery of both the more forceful and more subtle vase breathing methods continues throughout tummo practice, and so skill in this is a prerequisite.

When these three have been established, we are ready to practice tummo. 

The Practice

Continuing vase breathing, we straighten the spine even more with arms braced against the back of the palms in the lap. The focus is on the navel chakra with its inherent fire of chandali. Igniting the fire through visualization of the winds from below and above provides the foundation. Then, step by step, the practitioner moves the winds into the central channel up through the chakras, eventually mixing the cool energy of the masculine at the crown with the fiery energy of the feminine at the navel. This fans the flames of chandali, fierce inner heat, experienced as intense streams of bliss through body and mind. Tummo invokes bliss as the method, and with proper guidance and refinement, ordinary bliss can become great bliss (dewa chen; mahasukha), described by Chögyam Trungpa Rinpoche in this way:

[M]ahasukha is an actual experience of bliss, a physical, psycholo­gical, total experience of joy that comes from being completely without discursive thoughts, being completely in the realm of nonthought. It is uniting with the nondual awake state of being.

Mahasukha sets the stage for the practice of the other five Dharmas, which more fully develop the wisdom of this awake state of being.

Benefits of the Practice

The practice has effects both physical and mental. Mentally, this fire has the ability to burn conceptuality, dualistic clinging, and emotional obscurations and blockages so that we can clearly experience the true nature of reality cultivated through the profound practices of Mahamudra and Dzogchen. Tummo practice elicits intense blissful energy in the body, more intense than sexual orgasm, eventually bringing physical radiant heat and a luminous glow. Milarepa reports many other physical effects, including sweet body fragrance, toleration of heat and cold, the decrease of saliva and mucus, and overall experience of lightness and physical comfort no matter what the posture. He also speaks of the yearning for solitude and the decrease in reliance on food and sleep.   

It’s important to recognize that tummo is an advanced practice designed for solitary retreat, building on the foundation of meditation maturity gained through a close and trusting relationship with a guru, the completion of foundation practices, deity yoga sadhanas, and formless practices, as well as close personal guidance and preparation to enter the yogic path of the Six Dharmas. Additional support comes from the yogic exercises (trulkor) that prepare the embodied mind for deep practice. Improper preparation and motivation can bring disastrous results, such as extreme mental states like depression, severe anxiety, or disassociation, as well as physical illnesses. This is why the specific instructions and detailed visualizations for the practice are kept private between lineage guru and disciple, in order to ensure their inaccessibility for the unprepared or unsuitable practitioner.

The Science & Purpose of Tummo

Does tummo practice actually generate physical heat in the practi­tioner’s body? Belgian-French explorer Alexandra David-Neel reported in 1929 that she witnessed Tibetan tummo practitioners being led to the shore of an icy river or lake on a windy winter night, to be tested on their practice. There they sat, cross-legged and naked. They were then wrapped in cotton sheets freshly dipped in the icy water and were asked to dry them with their tummo practice. When dry, each sheet was freshly dipped and wrapped, repeating the process until daybreak. David-Neel describes seeing steam rising from the bodies of the yogis into the night air. The yogi with the greatest number of dried sheets—some were reputed to produce up to forty—was declared the winner. 

Contemporary scientists have conducted experiments with tummo practitioners to determine changes in body temperature generated by the practice. A 1982 study led by Herbert Benson measured skin temperature at different points of seasoned tummo practitioners’ bodies and found three- to eight-degree centigrade changes in a fifty-minute tummo session. A 2013 study led by Maria Kozhevnikov found increases in core body temperature in both seasoned and novice meditators. Substantially more significant and enduring changes occurred in the seasoned practitioners, but even novice meditators employing supervised, forceful vase breathing without visualizations or traditional elements were able to raise their body temperatures briefly into the fever zone.

These scientific studies, however, miss the actual purpose of tummo, which is to harness the fiery life-force of the body in service of the transmutation of turbulent emotions and conceptuality to reveal our nonconceptual wisdom, our inherent enlightenment residing in the body. While Milarepa’s light cotton robe was his trademark, his renown was based on his remarkable realization. To think that body heat or bliss experiences are the purpose of tummo is to mistake the trunk for the fruit, said Milarepa, in The Three Cycles of Illumination:

[Mind] illuminates itself by itself, illuminating within.
It’s like the dreams of a mute
Or the pleasure of a young person. 

For Milarepa, the realizations of tummo and the Six Dharmas are beyond intellect and speech, and the practice of tummo without proper motivation and guidance from an authorized teacher is like donkeys following lions jumping a ravine or foxes imitating tigers in the charnel ground. The results will be merely conventional and could be disastrous. Yogic realization of the true nature of mind through tummo must be experienced to be known. 

Judith Simmer-Brown

Judith Simmer-Brown is Distinguished Professor of Contemplative and Religious Studies at Naropa University and a senior Buddhist teacher in the Shambhala Buddhist tradition.