In this study, we focused on temperature and current distributions in voltage-state large-size intrinsic Josephson junction (IJJ) mesas with a self-heating effect. Because it is difficult to experimentally obtain temperature and current distributions in IJJ mesas, we numerically computed these distributions by solving non-linear diffusion and temperature dependence circuit equations. The local temperature in the mesa exceeded the critical temperature, and a normal-state appeared in the high bias region. Non-uniform temperature and current density distributions were obtained for each bias point of the current-voltage (I-V) characteristics. Normalized c-axis current distributions decreased with an increase in the bias current in the high bias regions. These results were explained using temperature dependent c-axis resistivity.