Cold wrapped in fire is a more complex pathogenesis of lung disease, mainly due to lung heat and external cold, i.e. external cold and internal heat. Because of the nature of the cold evil, after attacking the body, it will cause the Qi to converge and the couples to be closed, while the fire and heat in the body cannot be propagated to the outside, and is wrapped by the cold evil, so it is called cold encapsulating fire. The clinical manifestation is a mixture of cold and heat symptoms, which can include external cold symptoms such as cold, headache, cough, body aches and fever, and heat symptoms such as dry mouth, sore throat, coughing yellow phlegm, short and red urine, and dry stools. In treatment, the main method should be to relieve superficial heat and clear heat, dispersing superficial cold and clearing internal heat. The representative formula is Ma Heng Shi Gan Tang, which uses ephedra to disperse cold by sweating and gypsum to clear internal heat and stagnation by its cold nature. Cold encapsulating fire evidence, mostly seen in cough and croup. The onset of the disease is more acute, the condition is more serious, and the disease is often more dangerous.