heatloss

2. In science, the movement of thermal energy from a warmer object to a cooler one.

Heat loss from the hot cup made the coffee cool down.

3. In buildings, the amount of warmth that escapes through walls, windows, or roofs.

Double-glazed windows reduce heat loss from the room.

4. In the body, the way humans and animals give off warmth to stay at the right temperature.

Sweating helps with heat loss when you exercise.

5. In engineering, wasted energy that turns into heat instead of doing useful work.

The machine's heat loss meant it needed a cooling fan.