We investigated the thermal effects induced by pulsed laser absorption in an optical medium. In particular, the dependences of maximum temperature increment and decay time constant on the laser pulse width were examined. As the laser pulse width was increased, the maximum temperature increment was decreased and the decay time constant was increased. It was found that the temporal behaviors of the temperature increment could be predicted by the convolution of the response function of the system with a very short laser pulse and a square pulse function corresponding to the laser pulse width.