A second order mode-conversion equation is derived for ion-cyclotron resonance heating, by treating the ion Bernstein wave as a driven response to the fast Alfven wave. This equation is integrated numerically, and the results agree well with those obtained using higher order equations. It is then used to investigate the effects of introducing a small proportion of high-temperature fusion products into the plasma. These hot alpha particles absorb significant quantities of power, especially at low damping levels when the bulk of the plasma absorbs very little.