Master Heat & Radiation 2026 – Blaze Through Your Practice Test!

Insulated clothing works by increasing the resistance to heat flow between your body and the surroundings. Its goal is to keep the warm inside from slipping out to the cooler outside environment. Heat always moves from warmer to cooler areas, so when you wear insulating layers, the material—often with trapped air pockets and low thermal conductivity—slows that transfer, helping you stay warm.

So the best description is that it slows down the transfer of thermal energy from inside to outside the coat. Keep in mind that insulation can also reduce heat gain from a warm environment, but the practical and most important effect for keeping you warm is minimizing heat loss from your body.