In a p-n junction diode, the current-voltage (V-I) relationship is given by the diode equation: $I = I_s (e^{qV/kT} - 1)$, where $I_s$ is the reverse saturation current, $k$ is the Boltzmann constant, and $T$ is the absolute temperature. The reverse saturation current $I_s$ is highly sensitive to temperature because it depends on the intrinsic carrier concentration, which increases significantly with heating. Furthermore, the thermal voltage term ($kT/q$) in the exponential function implies that the forward bias current also changes with temperature. Therefore, a change in temperature due to heating affects both the forward and reverse bias regions, meaning it affects the overall V-I characteristics of the diode.