Tumo
"Inner heat (gtum mo, skt. chandali, literally meaning āfierce, hot or savage womanā) practice is the foundation for the rest of the six dharmas and is the first of the six dharmas.[9][10] This practice works with the subtle body (also known as the vajra-body) system of channels (nadis), winds (lung, vayu), drops (bindus) and chakras. Through inner heat, the vital winds are caused to enter into the central channel (avadhuti), causing the four blisses or joys which is then unified with the wisdom that understands emptiness.[9]
This practice is a kind of pranayama, that generally involves sitting with a straight back, visualizing the channels, holding the breath deep in the abdomen for extended periods (called āvase breathā, kumbhaka), then applying visualization of a fiery short stroke AH syllable on the navel. This practice leads the vital winds into the central channel, where they are said to melt the drops (bindus, which are tiny spheres of subtle energy) causing great bliss.[11] This powerful bliss experience āis said to constitute a similitude of the actual bliss experienced in spiritual awakening (byang chub, bodhi).ā[12]
According to Glenn Mullin, tantric scriptures state that the tantric bliss experienced in this practice is āa hundred times more intense than ordinary sexual orgasm, [and] gives rise to a special state of consciousness.ā[13] This ecstatic state of mind is then used to contemplate emptiness. This āecstasy conjoined with (the wisdom of) emptinessā[13] is what is referred to as Mahamudra (āGreat Sealā).[13]
Upside down Tibetan script Haį¹ seed syllable
Tilopaās verses of the six dharmas briefly outlines the practice as follows:
The yogic body, a collection of energy channels, coarse and subtle, possessing the energy fields, is to be brought under control. The method begins with the physical exercises. The vital airs [i.e., energies] are drawn in, filled, retained and dissolved. There are the two side channels, the central channel avadhuti, and the four chakras. Flames rise from the chandali fire at the navel. A stream of nectar drips down from the syllable HAM at the crown, invoking the four joys. There are four results, like that similar to the cause, and six exercises that expand them."
source: Tummo - Wikipedia
