This part of IEC 62240@ which is a technical report@ provides information when using semiconductor devices in wider temperature ranges than those specified by the device manufacturer. The uprating solutions described herein are considered exceptions@ when no reasonable alternatives are available; otherwise devices are utilized within the manufacturers?? specifications. The terms ??uprating?? and ??thermal uprating?? are being used increasingly in avionics industry discussions and meetings@ and clear definitions are included in Clause 3. They were coined as shorthand references to a special case of methods commonly used in selecting electronic components for circuit design. This document describes the methods and processes for implementing this special case of thermal uprating. All of the elements of these methods and processes employ existing@ commonly used best engineering practices. No new or unique engineering knowledge is needed to follow these processes@ only a rigorous application of the overall approach. Even though the device is used at wider temperatures@ the wider temperatures usage will be limited to those that do not compromise applications performance and reliability@ particularly for devices with narrow feature size geometries (for example@ 90 nm and less). This document does not imply that applications use the device to function beyond the absolute maximum rating limits specified by the original device manufacturer and assumes that: ?C device usage outside the original device manufacturers?? specified temperature ranges is done only when no reasonable alternative approach is available and is performed with appropriate justification; ?C if it is necessary to use devices outside the original device manufacturers?? specified temperature ranges@ it is done with documented and controlled processes that assure integrity of the electronic equipment.