There is fire element in the base chakra. Do you know, whenever you are eating food, the brain sends some signals and enzymes get created in the body? Do you know about it? Soma is that cooling fluid which is generated from top chakra. Life is a combination of Soma and Fire, the cool and the hot. There is the fire element in the Mooladhara Chakra, Swadisthana Chakra, Manipura Chakra and sometimes in the Anahata chakra also.
Sometimes we say that I have fire burning in my heart', isn’t it? So, in these 4 lower chakra’s the fire element is dominant. And the upper three chakras have the cooling element dominant. If you see, it is said that the third eye which is related to anger, has fire element dominating. We never say that we have feeling of fire in our throats. When we feel sad or very grateful the throat gets choked. So Somras is the fluid which is released from the brain and flows downward in the body, and the fire element rises upwards from the lower chakras. They meet at the Anahata (Heart) chakra and that is what is called Agnistoma. This is what is the essence of the Vedas - the technique of meditation that creates equilibrium between the hot and the cold, which creates a positive balance.