Evaporative cooling causes the chill

Steps:

• Swimmer exits pool with water on skin.
• Water evaporates into warmer air.
• Evaporation absorbs heat from body.
• Skin cools, triggering cold sensation.

Why D is correct:

• Evaporation is a cooling process where water molecules gain kinetic energy from the body as latent heat of vaporization, lowering skin temperature per the principle of evaporative cooling.

Why the others are wrong:

• A: Body temperature doesn't drop immediately; the sensation arises from localized skin cooling.
• B: Muscles and organs continue normal heat production via metabolism.
• C: Sunlight warms the body, not triggers heat loss in the hypothalamus.

Final answer: D