Hardware design engineers usually meet a temperature range as a single datasheet line: -20°C to +105°C. Once that line clears the enclosure requirement, attention moves to pin count, current rating, and mating height. Inside the connector, the range is a sequence of mechanical events. Each warm-up and cool-down pushes parts against one another, shifts a mating surface by a small amount, and sends strain through a solder joint. Reading that chain turns wide-temperature reliability from an abstract label into a design subject: where dimensional change lands, which material pair controls it, and how a 40A load changes the thermal picture. The practical outcome is a connector choice that preserves dimensions and contact force through field temperature swings, not merely one that matches a specification row.