It is correct to say that a cold and fever is the body’s way of protecting itself. Fever is a rise in body temperature due to the disruption of the central nervous function that regulates body temperature caused by the invasion of foreign pathogens such as viruses and bacteria. When a foreign pathogen invades the body, the body’s immune system kicks in, i.e., humoral and cellular immunity. The increase in the number of leukocytes can enhance the detoxification function of the liver and the speed of material metabolism. With the increase in blood circulation after the rise in body temperature, the leukocytes can find the invading pathogens through deformation and wandering to destroy them quickly. And the increase in body temperature makes viruses and microorganisms less active, and the phagocytes’ phagocytosis will be strengthened. However, prolonged fever will lead to the body’s organ function and metabolism to produce obstacles. So when the cold fever can be through physical cooling, such as ice packs, if necessary, use antipyretic ibuprofen and other ways to lower the temperature. If the fever does not go down for a long time, it is recommended to consult a doctor in time to avoid delaying the condition.