What causes crews to have difficulty seeing through windows with thermal imaging systems?

Thermal imaging systems detect heat emitted by objects, providing visibility in conditions where regular vision might fail, such as darkness or obscured environments. However, glass surfaces can pose a significant challenge for thermal imaging. The reason is that thermal radiation reflects off glass surfaces, causing the system to misinterpret the heat signatures that it is designed to detect.

When thermal imaging systems are aimed at windows, the glass can reflect thermal radiation from objects outside or inside the structure, leading to a distorted or obscured image on the display. Instead of accurately detecting the thermal signatures of people or objects located on the other side of the glass, the system may show reflections or irrelevant thermal information. This reduces the effectiveness of thermal imagery for direct observation through windows, making it difficult for crews to assess the situation accurately.