What should pilots ensure when operating in temperature ranges close to the limits?

When operating in temperature ranges close to the limits, pilots should focus on careful monitoring of engine parameters. This is crucial because extreme temperatures can affect engine performance and overall aircraft systems. Close monitoring allows pilots to identify any anomalies or potential issues that may arise due to temperature stresses.

In high or low-temperature scenarios, the engine may operate differently than expected. For example, a hot day could lead to decreased engine performance due to reduced air density, while colder temperatures might cause different responses in fuel flow or engine efficiency. By carefully observing engine parameters, pilots can ensure the aircraft remains within operational limits and respond promptly to any deviations.

The other options might address broader safety or operational considerations but do not specifically target the immediate requirement to monitor engine health in extreme temperature conditions. Higher fuel reserves, adjustment of flight altitudes, and training for emergency procedures are all beneficial practices, yet they do not provide the same level of immediate and focused oversight on engine performance, which is essential during temperature extremes.