An analysis is made of the ion energy balance equation for the ionosphere including the effects of O+, He+, and H+ ions, thermal conduction, and the cooling by atomic hydrogen and hylium. It is shown that thermal conduction strongly affects the ion temperature profile for conditions of moderate and low electron densities and that the high altitude ion temperature can be significantly less than the electron temperature. In addition, H+ in concentrations as low as 10% of the total ion density is found to be a major recipient of heat from the ionospheric electron gas and has an important influence upon the total ion energy budget.