Self-consistent calculations of energy loss for a Ga ion moving in hot Au plasmas are made under the assumption of wide ranges of the projectile energy and the plasma temperature with all important mechanisms considered in detail. The relevant results are found to be quite different from those of an a particle or a proton. One important reason for this is the rapid increasing of the charge state of a Ga ion at plasma temperature. This reason also leads to the inelastic stopping which does not always decrease with the increase of plasma temperature, unlike the case of an a particle. The nuclear stopping becomes very important at high enough plasma temperature due to the heavy reduced mass of a Ga and an Au ion and the above-mentioned reason. The well-known binary collision model [Phys. Rev. 126 (1962) 1] and its revised one [Phys. Rev. A 29 (1984) 2145] are not working or unsatisfactory in this case.