Heat is associated physically with light, as love is associated with intuitive knowledge and organic life with the instrumentality of the spirit. According to Plutarch, heat and light were set in motion by the Sun, just as were the intellectual and vital principles, blood and breath, by the heart. This has a slight notional similarity with Tantrism. In depicting the Sun, its heat is shown by wavy lines, its light by straight lines.
Heat is a cosmic power which, according to the Rig-Veda, allowed the One to be born from primordial Chaos. The incubation of the World Egg has often been compared with that of the hen’s egg, life being equally present in both, as The Secret of the Golden Flower observes, ‘through the powers of heat’. This is, in any case, merely a symbol of the concentration of the spirit within the heart to give birth to ‘the embryo of immortality’. In this respect heat is the principle of rebirth and regeneration, as well as of communication, playing this part at all sacrificial feasts and at all banquets and celebrations. Thus Jung makes it an image of the libido. Its action is all the swifter and more effective if the recipient, through natural sympathy, is more open to its influence.
In Yoga, heat is tapas, which also means ascetic discipline. The acquisition of internal fire is sometimes taken literally. In Shamanism and also in Tibetan g’Tummo, this takes the form of an extraordinary resistance to external cold. These are, however, subsidiary manifestations since tapas is the heat internalized, the flames of the spirit and the destruction by fire of sense-perceptions and of the limitation on the individual’s existence. Furthermore, in Tantrism the element Fire corresponds to the anahata-chakra, the centre of the heart. Some Buddhist schools practise meditation on the element Heat (tejodhatu); however, the feeling of heat is particularly associated with the raising of energy in KundalinI Yoga and is readily compared with a blazing fire. Some writers maintain that this heat is a consequence of ‘raising’ and sublimating sexual energy. This is what The Secret of the Golden Flower calls the ‘kindling power’ of the breath of the ‘pre-existent Heaven’. The Pali Buddhist canon itself links the acquisition of heat with the control of respiration.
At a different level, heat is identified with the ‘anger’ of initiation into warrior castes, linked to the acquisition of some psycho-physical ‘power’. As is often the case, such an acquisition carries its own dangers with it. In any case ‘anger’ and ‘heat’ may also spring from satanic influences which it is as well to exorcize. Shanti (peace) is literally putting out ‘fire’.
It should also be observed that in Ancient China fire and heat were associated with drought and rain-making and also, as is universally the case, with the colour red. The ideogram ch’e also gives the meaning of drought. It is literally ‘man’s fire’, which would link it with the meaning of anger.
In the Celtic world, heat is often related to a hero’s or an individual’s warlike valour. Irish heroic literature mentions several warriors, and especially Ciichulainn, who melted the snow for thirty feet around them. Since heat and warlike frenzy go together, this is probably the reason why the Ancient Celts fought stark naked, as Classical authors so often record.