This study aimed to investigate the influence of temperature on the reliability of an ultrathin-body double-gate ferroelectric tunnel field-effect transistor (UTB-DG-FE-TFET). An in-depth simulation-based analysis of the fluctuation in DC parameters including transfer characteristics, subthreshold swing (SS), and I_ON/I_OFF ratio is provided across a whole temperature range from 200 K to 400 K. The proposed device is contrasted with a standard FE-TFET model in terms of RF figure of merit (FoM). A technology computer-aided design (TCAD) simulator is also used to examine the RF/analog performance of the proposed device in terms of temperature. This study additionally investigates the impact of temperature on voltage intersect points (VIP2 and VIP3), third-order power intercept points (IIP3), higher-order harmonics (gm2 and gm3), and third-order intermodulation distortion (IMD3). To assess the device's linearity, temperature variations are employed on the 1-dB compressive point. The effect of temperature on drain current at various gate voltages is further examined employing various models. An extremely notable technology for minimally powered large-frequency uses, the ON-state current displays almost no influence from fluctuations in temperature. A careful evaluation of all the performance characteristics of the proposed device is advantageous from the standpoint of design. This implies that the proposed device is more reliable than standard TFETs in lower-power applications at elevated temperatures.