Which sign is not typically associated with malignant hyperthermia?

• A. Tachycardia
• B. Rigid jaw
• C. High fever
• D. Hypothermia

Answer: (D)

Malignant hyperthermia is a life-threatening hypermetabolic reaction to certain anesthesia drugs, caused by abnormal calcium handling in skeletal muscle. This leads to rapid heat production and CO2 buildup, triggering a cascade of signs such as a fast heart rate, muscle rigidity (including jaw rigidity), and a rising body temperature as the crisis progresses. Because the process generates heat, hypothermia does not fit with this pattern and is not typically associated with malignant hyperthermia. In contrast, tachycardia and jaw rigidity are classic early indicators, and fever (hyperthermia) is a hallmark as the condition unfolds. Prompt recognition and treatment with dantrolene and cessation of triggering agents are essential to reverse the crisis.