Body's thermoregulation response to heat

Steps:

• External temperature rises, triggering hypothalamus to activate cooling mechanisms.
• Sweating increases to promote evaporative cooling from skin.
• Skin blood vessels dilate (vasodilation) to increase blood flow and heat loss to environment.
• These changes lower core body temperature efficiently.

Why C is correct:

• Thermoregulation law: In hot conditions, sweating and vasodilation dissipate excess heat via evaporation and radiation.

Why the others are wrong:

• A: Describes cold response, where vasoconstriction conserves heat and sweating decreases.
• B: Vasodilation is correct for heat, but sweating decreases is a cold adaptation.
• D: Sweating increases for heat, but vasoconstriction retains heat inappropriately.

Final answer: C