Cold (Han)

Associated with Winter and the Water Phase, Cold slows, obstructs, blocks and hardens, causing contraction and severe, sharp, biting pains.

The body becomes cold and underactive, and secretions (urine, stool, phlegm, for instance) become watery, clear and copious.

Heat (Re)
Associated with Summer and the Fire Phase, Heat warms, activates, and moves to produce redness, inflammation and fever. It causes reckless movement, injures the Blood and damages Body Fluids.

People become restless and irritable; secretions become thick, hot and yellow. An acupuncturist will often ask about the nature of a patient's phlegm, and look at the coating on their tongue in order to differentiate between Cold and Heat.