A vest consisting of a battery or power source, a pump, and an ice/water or cooling agent container where the cooling agent is circulated throughout the garment and operates on the principle of conductive heat transfer is known as a(n) __________ vest

• A. Water cooled
• B. Air cooled
• C. Ice cooled
• D. Hybrid cooled

Answer: (A)

Active liquid cooling uses a circulating coolant to remove heat from the body. The vest described relies on a pump and a power source to push the cooling agent through tubing and through the garment, with the agent absorbing body heat by conduction as it flows. Because water-based coolants have high heat capacity and transfer heat efficiently when circulated, this setup excels at carrying heat away via conduction, which is why the garment is a water-cooled vest. Air-cooled designs rely on ambient air and don’t circulate liquid through the garment, ice-cooled vests use static ice packs, and hybrid systems combine methods not described here.