noun
heated wire; hot wire
Refers to a wire that becomes hot when electricity passes through it, used in heaters, toasters, and similar devices.
このヒーターは熱線で温まります。
This heater warms up using a heated wire.
noun
infrared rays; heat rays
Often used in technical or scientific contexts; synonymous with 赤外線 (infrared rays).
See also: 赤外線
熱線カメラで夜の動物を観察する。
Observe nocturnal animals with an infrared camera.