The present work focuses on the analysis of the extreme conditions encountered during the process of collapse of cavitation bubbles. The objective is to characterize the temperature variations inside the vapor/gas bubble, and also in the surrounding liquid. This information is especially relevant to address the issues of cavitation erosion and develop appropriate models that take into account the thermal effects in cavitation. The work is based on an experimental approach where temperature measurements are performed with cold wires technique. This technique is characterized by a very small time response, and can be applied to both phases during the growth and collapse of the bubbles.