Which sign is characteristic of moderate hypothermia?

• A. Nausea
• B. Rigidity
• C. Headache
• D. Dizziness

Answer: (B)

Moderate hypothermia shifts the body's response from active heat production to a general slowing of function, so signs become more about impaired neuromuscular performance than active heating. As core temperature drops into the moderate range, shivering often diminishes or stops because energy reserves are depleted, and muscles can become stiff. This muscle rigidity is a relatively specific indicator that the body's thermoregulation has progressed beyond the mild stage, making it a characteristic sign of moderate hypothermia. The other symptoms listed—nausea, headache, and dizziness—are nonspecific and can occur with various conditions, including mild hypothermia or other illnesses, so they don’t point as clearly to the moderate stage.