A series of experiments has been carried out with the aim of determining the temperature distribution in nervous tissues after coagulation, vaporization and cutting, using electrosurgical unit (monopolar mode and bipolar mode) and laser beam (CO2, Argon and Nd:YAG). It was found that, at a surface distance of 2 mm from the heated point, the superficial temperature reaches different values, ranging from 100 degrees C, to 15 degrees C, 8 degrees C, 6 degrees C, 10 degrees C using monopolar mode, bipolar mode, CO2 laser, Argon laser and Nd:YAG, respectively. At a depth of 2 mm below the target point, however, the temperature increase is drastically reduced.