How should cooling be evaluated for a Raspberry Pi 5 with an AI HAT?

Use the actual enclosure, ambient temperature range and continuous workload. Log temperature, operating frequencies and application latency over a long enough period to reach a steady condition. A short benchmark can finish before heat accumulation exposes a problem.

Follow the accessory's cooling and mounting guidance, including clearance around the Pi cooler and any HAT heatsink. Check that stacking hardware does not obstruct airflow or contact components incorrectly. Evaluate the combined assembly, because changing one heatsink can affect the other device's airflow.

Compare sustained throughput and worst-case latency before and after a cooling change. Also check fan power, noise and dust exposure if relevant to deployment. Choose operating limits from the device documentation rather than treating an arbitrary temperature target as a universal requirement.