Electromagnetic ion cyclotron (EMIC) waves in the H+, He+, and O+ bands are frequently observed in the magnetosphere. This study examines the effects of the thermal pressure of heavy He+ and O+ ions on EMIC wave properties. It illustrates that hot and isotropic heavy ions may completely suppress the growth of He+ band EMIC waves, whereas H+ band waves are growing irrespective of whether the heavy ions are cool or hot. At large O+ ion concentration, O+ band waves grow considerably as hot protons, and heavy ions are anisotropic. Results from the hot fluid model show that anisotropic thermal pressures of heavy ions result in the resonance frequency of EMIC waves larger than that from the cold fluid model, and therefore, narrowing the corresponding stop bands. Furthermore, the anisotropic ion thermal pressures lead to the minimum resonant energy of electrons interacting with EMIC waves at higher frequencies than that predicted by the cold fluid model. Published by AIP Publishing.