Resonance lines of highly ionized H and He-like ions and their associated satellite lines are used to determine the electron temperature and the transient state of the plasma in solar flares. The intensity ratio of the satellite lines 1s2nl-1s2pnl to the resonance line 1s2-1s2p has been calculated for the n = 2, 3 and 4 shells of Fe XXIV. The results have enabled the identification of many lines in the only available high resolution solar flare iron spectrum and give a good estimate of the spectral intensity in the resonance line by evaluating the contribution due to the blending of the satellites with n ≥ 3.