This pattern is classified as ‘Exterior’ not because it derived from an external pathogenic factor but because its manifestations are located in the ‘Exterior’ of the body (the skin, muscles and channels).

'Cold' here is an exterior pathogenic factor. Spontaneous 'Fever' and aversion to cold are the typical manifestations. The Cold constrains the skin pores and thus there is no sweat.

Aversion to cold refers to the sudden chilliness and dislike coldness when patients get sick with a cold or other acute diseases. ‘Fever’ (发热 /Fa Re) does not necessarily indicate an actual fever, but rather the patients' objective feeling of the heat.

Wind is a pathology that commonly accompanies Cold Evil. External Wind can also refer to the proliferation of various bacteria and viruses in additional to actual windy environment. The fact that the Chinese character for Wind is a small insect might perhaps suggest that they suspected the existence of external pathogens such as germs and viruses.

The combined Wind-Cold invasion is an Exterior-Excess pattern and Ma Huang Tang is commonly used.

If the pattern is rather Exterior-Empty, which means the Cold exists due to lack of Yang element, Gui Zhi Tang is more recommended.