Temperature is the most fundamental—and most brutal—physical parameter influencing the reliability of materials, components and complete systems. GB/T 2423.1, GB/T 2423.2, GJB 150.3A, GJB 150.4A, DO-160 Section 4/5, IEC 60068-2-1/-2 and MIL-STD-810H all quantify requirements for temperature slew rate, dwell time, heat load and measurement uncertainty.