Which term describes the use of external heat from the environment to raise body temperature?

• A. Passive Rewarming
• B. Active Rewarming
• C. Afterdrop
• D. Heat Cramps

Answer: (A)

Using external heat from the environment to raise body temperature is passive rewarming. This approach relies on the surroundings—like being in a warm shelter, wrapped in dry blankets, or wearing insulating clothing—to reduce heat loss and allow the body’s own heat production to recover gradually. It does not actively add heat to the body. In contrast, active rewarming uses external heat sources to raise core temperature more directly, such as warm blankets with radiant heaters, heated fluids, or forced-air warming. The other options refer to different phenomena: afterdrop is the continued fall or redistribution of heat after some rewarming has begun, and heat cramps are muscle cramps caused by dehydration and electrolyte imbalance under heat stress. Passive rewarming is the appropriate term for harnessing environmental heat to increase body temperature.