“伤寒，医以丸药下之，身热不去，微烦者， 栀子干姜汤主之。”

“In cold damage, (which was) treated with a great purging pill; (if) the fever has not abated (and there is) slight vexation, Zhī Zǐ Gān Jiāng Tāng governs”.

This formula treats cold damage following major purgation (manifesting with) body heat and slight vexation.
(Here) major purging has injured center qì, with turbid yīn ascending counterflow, and the generation of stasis, (which) injures the bowels (fǔ organs); this results in obstruction to imperial fire, which is unable to descend, therefore there is body heat and heart vexation. Zhī Zǐ Gān Jiāng Tāng is used, as gān jiāng descends counterflow and warms the center, while zhī zǐ ejects stasis and eliminates vexation.

Zhī Zǐ

Bitter flavor, cold nature; enters the hand shào yīn heart, foot tài yīn spleen, foot jué yīn liver, and foot tài yáng bladder channels.
Clears heart fire and eliminates vexation depression, drains spleen earth and eliminates damp heat. (It) ejects turbid stasis from the chest and diaphragm and cools smokey-yellowing from the skin.

Gān Jiāng

Acrid flavor, warm nature; enters the foot yáng míng stomach, foot tài yīn spleen, foot jué yīn liver, and hand tài yīn lung channels. (Gān Jiāng) dries dampness, warms the center, moves depression, downbears turbidity, supplements and boosts fire (of the) earth, breaks up the absorption of water and grains, warms the spleen, stomach and extremities; regulates yīn and yáng and settles nausea and vomiting; downbears turbid counterflow, calms coughing, lifts desertion and sinking and stops efflux diarrhea.

**Above medicinal info translated from ‘Huáng Yuán-Yù’s Interpretation of Medicinals’ (黄元御药解)