What is the greatest risk of hypothermia?

• A. when immersed in cold water
• B. in direct sunlight
• C. in dry clothing
• D. after exercise

Answer: (A)

The main idea is that heat loss determines the risk of hypothermia, and being in cold water causes heat to leave the body far more quickly than any other scenario listed. Water conducts heat away from the body about 25 times faster than air, so when you’re immersed in cold water your core temperature drops rapidly. Wet skin and clothing also transfer heat away faster, making the onset of hypothermia happen sooner than in dry air. Direct sunlight tends to warm you rather than cool you, dry clothing provides insulation to slow heat loss, and while stopping exercise can reduce heat production, it doesn’t pose the immediate, rapid heat loss that cold water immersion does. So, being immersed in cold water is the greatest risk because it accelerates all the factors that lead to hypothermia.