Name two devices used to detect heat or locate fires within walls or ceilings and describe their primary use.

• A. Carbon monoxide detector; measures breathing air quality.
• B. Anemometer; measures wind speed.
• C. Digital camera; captures images.
• D. Thermal imaging camera (TIC) to locate hidden fires and hotspots; infrared scanning to identify heat signatures and assess fire spread behind walls or ceilings.

Answer: (D)

The main idea is using heat-detecting tools to reveal fire activity that isn’t visible to the eye. A thermal imaging camera senses infrared energy emitted by objects and converts it into a visual image that shows where heat is concentrated, allowing you to spot hidden fires and hotspots behind walls or ceilings. Infrared scanning is the method these devices use to map those heat signatures across surfaces, helping you assess heat spread and locate concealed flames even through smoke or darkness. That combination is why this choice is best: it directly reveals heat and hidden fire, which ordinary cameras or air-quality devices cannot do. For context, carbon monoxide detectors measure air quality, not heat; anemometers gauge wind speed; and a digital camera only captures visible light, not heat signatures.