From: Handpicked Cases of Famous Cold Damage Physicians, by Chén Míng (陈明, 伤寒名医验案精选） 

Treatment of a mismanaged case 

A forty-year-old male presented at the clinic with non-receding copious sweating and coldness following a fever from the common cold. On inquiry he mentioned that he did not suffer from headaches, coughing, or painful extremities, and only felt weak and fatigued. In addition, for the last ten years his bowel movements were disturbed. His pulse was deep, thin and lacked strength, and his tongue had a thin-white slippery coat. A physician he had previously seen after hearing that the patient had contracted the common cold, manifesting with body coldness, prescribed Shēn Sū Yǐn (Ginseng and Perilla Decoction).
I personally feel that this formula should be used for treating deficient patients that contract an external pathogen and have simultaneous retention of phlegm and thin-fluids. Currently this patient did not have any signs or symptoms of an external attack, and merely had copious sweating and coldness following a common cold fever. This belonged to a deficiency of defensive qì, and administering Shēn Sū Yǐn (Ginseng and Perilla Decoction), which is a warm-scattering formula, would fail to stop the sweating and intensify the aversion to cold.
I changed the formula to guì zhī jiā fù zî tāng (Cinnamon Twig Decoction plus Aconite), and due to the long term draining creating an insufficiency of central qì, I added huáng qí (Astragali Radix). In addition, páo jiāng (Zingiberis Rhizoma preparata) was used instead of shēng jiāng (Zingiberis Rhizoma recens). After two packages, his condition had resolved. 

Commentary: If we look at this case from the disease history to the pattern, we see signs of deficiency. The previous physician failed to ask about the history, did not go over the disease mechanism, and failed to correctly examine the pulse. He administered the warm-scattering Shēn Sū Yǐn (Ginseng and Perilla Decoction), which inevitably caused copious sweating, and intensified the coldness. Dr. Qín took a very detailed account of the tongue and pulse signs, and was clear about the pattern identification. He made a diagnosis of a defensive qì deficiency, with central qì insufficiency, and administered guì zhī jiā fù zî tāng (Cinnamon Twig Decoction plus Aconite) with páo jiāng (Zingiberis Rhizoma preparata) instead of shēng jiāng (Zingiberis Rhizoma recens) and the addition of huáng qí (Astragali Radix).
By understanding the root of the disease, all it took were two packages for it to completely resolve.