In today's digital world, the demand for computer security and system reliability is a crucial element. Monitoring the CPU temperature during operation provides valuable insights but is currently limited to the embedded on‐chip sensors. The implementation of an extra security layer based on temperature monitoring can detect anomalies in an early stage, identify malware, and help mitigate attacks. The approach of integrating more on‐chip temperature sensors into the silicon is avoided due to space, power limitations, and cost constraints. However, the field of printed electronics and sensor technology has recently seen significant progress. This is the first work that introduces a fully‐printed temperature sensor array integrated onto the cooling unit of a CPU. It offers a novel approach for the practical implementation of such sensors into an operational computer system. The present sensor array, consisting of 396 sensor pixels, detects local hotspots induced by the underneath CPU cores, leading to an individual thermal fingerprint. This unique method paves the way for addressing pivotal elements of computer security, as deviations from expected thermal behavior can signal malicious activities. Additionally, this innovation facilitates reliability optimization. The detailed thermal map garnered provides insights into which cores are subjected to significant stress over time.