The monarch fire refers to the heart fire, or the yang qi of the heart, a term relative to the ministerial fire. The monarch fire warms and propels the activities of zang-fu organs. The heart is the monarch and governs five zang-organs and six fu-organs. It pertains to fire from the perspective of the five-element theory. Therefore, heart yang is called the monarch fire. It is the substantial source of life activities. The monarch fire has close relationships with heart spirit (mind, consciousness and mental activities) and heart’s function of governing blood and vessels (engendering and moving blood). Its opposite is the ministerial fire. The former is located in the upper energizer governing the whole body, whereas the latter is stored and hidden in the lower energizer nourishing and warming the zang-fu organs. These two types of fire mutually complement, inhibit and cooperate to warm the zang-fu organs and propel the growth and development of the human body.