A current is passed through a combination of two resistors...

The thermal energy produced in a resistor is given by $H = I^2Rt$.

Since both resistors are connected in series, the same current $I$ flows through them. Given that their resistances $R$ are equal, the thermal energy produced in both resistors over the same time interval $t$ must be equal.

The rise in temperature is given by $\Delta T = \dfrac{H}{ms}$, where $m$ is the mass and $s$ is the specific heat capacity of the resistor.

Since the material and mass of the two resistors are not specified, their heat capacities ($ms$) may or may not be equal. Therefore, an equal rise in temperature may occur, but it is not guaranteed.