A high fever after surgery is very dangerous, and the exact temperature of the fever should be at least 38°C or higher. Post-operative infections are divided into the following categories; surgical incision infections, nosocomial severe pneumonia, catheter-related blood circulation infections, urinary tract infections, and so on. However, regardless of the type of infection, when the inflammation is widespread, the body itself has an impaired immune system as a result of the surgical shock and stressful stimuli, so when a second infectious inflammation develops, it is usually very severe. In addition to an elevated body temperature, the patient will have an increased white blood cell count, a rapid pulse, increased respiration, decreased partial pressure of oxygen, and increased partial pressure of carbon dioxide, among other things. Once the infection is combined with the invasion of pathogenic bacteria and develops into sepsis, it has a mortality rate of up to 7%, which is why post-surgical infections, bleeding or other complications are so serious.