YMCA Basic Life Support (BLS) Training Practice Test

Shivering and altered mental status are classic signs of hypothermia, which occurs when the body loses heat faster than it can produce it, leading to a dangerous drop in core body temperature. Shivering is the body's initial response to generate heat through muscle activity. As hypothermia progresses, the body may struggle to maintain normal functioning, resulting in altered mental status, which includes confusion or lethargy. This combination of symptoms indicates that the body's thermoregulation is compromised, requiring immediate attention to prevent severe complications or even death.

The other choices do not align with the typical signs of hypothermia. Sudden weakness with blurry vision may suggest a range of medical issues but does not specifically point to hypothermia. Increased heart rate is generally associated with hyperthermia (overheating) or stress responses rather than hypothermia. Nausea and heavy sweating are more indicative of conditions like heat exhaustion or heat stroke, where the body is struggling to cool itself rather than losing heat, further supporting why shivering and altered mental status are the key indicators of hypothermia.