•Effects of different ventilated temperatures on cavity dimensions and distributions of the flow field inside the cavity were numerically investigated using fully compressible homogeneous multiphase flow.•Good agreement is obtained in comparisons of the cavity shape and cavity dimensions to the experimental data.•Detailed mechanisms of the ventilated cavity evolution were provided.•Effects of temperatures on cavity dimensions, distributions of the flow field inside the cavity, and on the instability of the gas-water interface were explained. Nowadays, with the widespread use of modern technology in underwater vehicles, particularly in naval applications, the artificial gas ejected from ventilated holes is normally heated because of engine operations. However, the dynamics of ventilated hot gas have not yet been fully studied. In this study, the cavitating flow around an axisymmetric body with different ventilated temperatures was numerically investigated. A fully compressible mixture model based on a homogeneous multiphase approach was employed. A high-order accuracy flow solver based on the numerical models of a dual-time preconditioning technique, a sharp interface-capturing scheme, and an enhanced cavitation model was used to examine the effects of temperature on the cavitating flow. First, the numerical results were validated by comparison with available experimental data of cavitating flow around a conical cavitator. Reasonable agreements on the cavity shape, cavity length, and cavity thickness were achieved. The solver was then applied in simulations to analyze the development of the ventilated cavity, including the cavity formation at the early stage, the re-entrant jet phenomenon, and the cavity shedding mechanism. In addition, the effects of ventilated temperatures on the cavity length and cavity thickness were studied. Further insight into the distributions of the flow field inside the cavity, and the instability of the gas-water interface when temperature increases were also provided.