The psychic heat "Drod" is produced by the space particles and the heat manifested from the friction of the wind element. This is another fundamental element as it supports and gives power to the consciousness, like the power of the fire that can launch rockets to space. The power is called "medrod" or 'digestion fire' in medicine and "Tummo" in yoga tantra. The heat (fire) sustains life and protects the body/mind. The psychic fire increases the wisdom, burns the ignorant mind of the brain and gives realization and liberation from the darkness of unawareness. That is why yoga describes "Tummo" as the aggressive fire which ignites from below navel, pierces the chakras one by one and reaches the sky of the crown chakra. The tummo burning arrow married with the celestial bride leads to enjoy the life of transformation of samsara. They give birth to the son of awareness from the blissful garden of Vajrayogini.