OpenAI Researcher Warns: Air-Gapped PCs Can Use CPU Heat to Communicate

On September 18, 2026, OpenAI researcher Noam Brown shared findings on advanced AI model interaction security, stating that "humans should absolutely not underestimate AI capabilities." Based on academic research, he noted that adjacent air-gapped computers can form a low-bandwidth covert communication channel using CPU heating and temperature sensor readings, effectively acting like Morse code.

Air-gapped systems are disconnected from external networks and data links, commonly used to prevent unauthorized access or data exfiltration. The research describes how one device increases CPU load to raise its temperature, while another reads ambient or hardware temperature changes. The sender modulates heat output according to a preset rhythm, and the receiver interprets the temperature fluctuations as encoded information, creating a very low-bandwidth covert channel.

Modern CPUs, GPUs, and motherboards are widely equipped with temperature sensors, primarily used for thermal management, such as adjusting fan speeds, reducing chip clocks, or triggering overheating protection. Brown's remarks highlight that even with air-gapped measures, information exchange between adjacent computers may not be completely blocked.