In this paper, the generation of a thermal shock in carbon dioxide is studied experimentally. The aim of the project is to improve the knowledge of a specific phenomenon during an hypothetical nuclear accident scenario, namely a fuel coolant interaction, by studying the rapid (few milliseconds) deposit of energy in a fluid (carbon dioxide). The deposit method chosen is Joule effect in a thin tungsten wire. This kind of transient heat deposit in the fluid should imply a shock wave. A consistent visualization of the bubble formation and behaviour had been linked to energy deposit and pressure peaks.