It is possible that the chills after surgery are caused by the following reasons: 1. It is possible that the side effects of anesthesia, especially general anesthesia, may lead to shivering and chills after surgery. 2. Especially the chest and abdomen surgery must be completely undressed before it can be carried out, and the temperature inside the operating room is about 20℃, so people with weak constitution can easily catch cold and flu during the surgery, and can have chills after the surgery.