What is a major sign of hypothermia?

Shivering is a major sign of hypothermia because it is the body's initial response to cold temperatures. When a person is exposed to cold conditions and their body temperature begins to drop, shivering serves as an involuntary mechanism to generate heat. Muscles contract rapidly, which produces warmth, helping to maintain the body’s core temperature. As hypothermia progresses, however, shivering may stop as the body becomes too cold to sustain this response, which can indicate a more severe stage of hypothermia.

The other options do not align with the physiological responses associated with hypothermia. Increased appetite is not a symptom of hypothermia; rather, individuals might lose their desire to eat as their metabolism slows. Rapid heartbeat could occur initially in response to cold but is not a defining characteristic of hypothermia. Excessive sweating typically indicates overheating or exertion and is not associated with the cold-induced condition of hypothermia.