Final answer:
The condition caused by an injection of succinylcholine that leads to a high fever is malignant hyperthermia, a serious reaction to anesthesia drugs.
Step-by-step explanation:
The condition triggered by an injection of succinylcholine (Anectine) that causes an unusually high fever is malignant hyperthermia. Succinylcholine is a medication used to induce muscle relaxation and is often used during the start of anesthesia. Malignant hyperthermia is a severe reaction to certain drugs used for anesthesia, like succinylcholine. This reaction causes a rapid increase in heart rate and body temperature, leading to muscle rigidity and other symptoms, and it can be life-threatening if not treated promptly with medications such as dantrolene.