What system alerts you to overtemperature conditions in the heating/defog ducting?

The system that alerts you to overtemperature conditions in the heating/defog ducting is based on temperature sensors. These sensors are specifically designed to monitor and measure the temperature within the heating and defogging systems. When the temperature exceeds a predetermined threshold, indicating an overtemperature condition, the sensors trigger alerts to inform the pilot and support crew. This function is critical for maintaining safety and functionality within the aircraft, as excessive temperatures can lead to equipment damage or failure.

While other systems such as pressure sensors or smoke detectors are important for different safety aspects, they do not specifically monitor temperature conditions in the heating/defog ducting. Humidity sensors are employed to measure moisture levels but are not directly involved in temperature management. Thus, temperature sensors are the appropriate and correct choice for this context.