The duration of post-operative fever is related to the cause of the fever, which usually resolves after 2-3 days of symptomatic treatment. A variety of conditions after surgery can cause postoperative fever, such as tissue and organ damage caused by surgery, pre-operative pre-existing infections that have not been controlled in time, and new postoperative infections that can cause fever. If the patient’s resistance is strong, the intraoperative injury is mild, and the original infection is effectively controlled through active anti-infection treatment, the fever generally subsides after 2-3 days. If the scope of intraoperative injury is larger or the complicated infection is not controlled in time, the fever can last longer and may even cause infectious shock, endangering the patient’s life. In addition, patients with postoperative hypothermia can be treated by physical cooling methods and generally do not require drug therapy. A body temperature over 38.5℃ can be treated with non-steroidal anti-inflammatory drugs to reduce fever.