Which of the following is a sign of hypothermia?

Shivering is a classic sign of hypothermia, which occurs when the body loses heat faster than it can produce it, often due to exposure to cold water or cold weather. When the body starts to cool down significantly, it activates involuntary muscle contractions, known as shivering, as a mechanism to generate heat to maintain core body temperature. This response is crucial, as it helps to stave off the effects of hypothermia.

In contrast, excessive sweating can actually lead to a loss of body heat and is not typically associated with hypothermia. Increased heart rate may occur in response to other conditions but is not a direct indicator of hypothermia and may not be evident during the initial stages. Warm skin is also an indication of adequate body heat, which contradicts the state of hypothermia where skin becomes cold as the body temperature drops. Therefore, shivering stands out as a primary and recognizable symptom of hypothermia.