Based on fundamental physics-based considerations, we introduce the Biaffine Temperature-Voltage power model (BiTV) for SoC systems, which takes the influence of dynamic voltage, frequency, and ambient temperature conditions into account. Using an ARM-Cortexbased AM572x system operating in a temperature-controlled oven, we provide experimental evidence of the validity of the BiTV power model over a significant range of ambient temperatures (25 to 55 °C), voltages (0.98 to 1.23 V) and frequencies (100 to 1,500 MHz). These experiments and the BiTV model provide quantitative elements to assess the impact of ambient temperature on systems’ performance. Such insights could be of use to system designers and compiler writers, in particular when dealing with embedded systems operating in harsh conditions or under energy-critical constraints.