A study of the modifications produced by high-power, high-frequency (HF) waves in the F region of a quiet (low solar cycle) polar ionosphere is presented. In the polar geometry, maximum ohmic heating occurs producing significant changes to the zero-order electron temperature and density profiles. The temporal and spatial aspects of these changes are calculated and their effects on relevant ionospherid parameters, such as the dc conductivity tensor are found. An interesting result is the generation of a density depression at the reflection point of the HF waves. The dependence of ohmic heating on HF pump parameters and peak background density is considered.