What symptom is indicative of severe hypothermia?

The symptoms of severe hypothermia include a notable decrease in the body's core temperature, which can lead to profound physiological changes. A critical sign of severe hypothermia is the absence of shivering, as the shivering reflex is one of the body’s mechanisms to generate heat. When hypothermia progresses to a severe stage, the body becomes too cold and loses the ability to shiver, reflecting a state of metabolic failure.

In addition to the cessation of shivering, the individual may also experience significant motor impairment, which can manifest as an inability to walk. This loss of coordination and strength results from decreased available energy and muscle function, making it a critical sign that medical intervention is necessary.

Other symptoms like rapid heartbeat, excessive sweating, or yellowing of the skin do not directly correlate with severe hypothermia. In fact, a rapid heartbeat is usually associated with mild to moderate hypothermia as the body attempts to combat the cold, while excessive sweating generally doesn't occur in hypothermia scenarios. Yellowing of the skin indicates liver issues rather than hypothermia. Therefore, the combination of no shivering and inability to walk clearly indicates a state of severe hypothermia that requires immediate attention.