The preferred direction of alignment of the liquid crystal molecules in nematics with two-fold degenerate alignment can be affected substantially by changing the temperature or by applying an electric field. As a result, an almost in-plane switching of the molecules occurs. Here, we report an opto-thermal reorientation effect in a nematic with two-fold degenerate alignment due to a local heating of the liquid crystal by a high power laser beam. The mechanism of this phenomenon is discussed. The opto-thermal reorientation of the molecules makes it possible to visualize the temperature distribution in the illuminated cell and some applications can be foreseen.