The linear stability of magnetospheric plasmas to low-frequency electromagnetic perturbations is investigated, for the case where there exist equilibrium density and temperature gradients, as well as temperature anisotropies. The effects of the temperature gradients on the behavior of drift-compressional modes are given special attention. The effects of a gradient in the equilibrium magnetic field, required for hydrostatic equilibrium, are included to lowest nonvanishing order. The model is valid for moderate &bgr; magnetospheric plasmas. A two-component (hot and cold) multispecies plasma is considered, and a kinetic linear dispersion relation is derived, for arbitrary Larmor radius ordering. The destabilizing effects of the gradient in the perpendicular temperature (orientations are measured with respect to the unperturbed magnetic field) are discussed.