pThe southern half of Europe is experiencing scorching heat this week. Temperatures are set to reach up to 40°C in certain parts of France this Tuesday. In Greece, several fires broke out on Monday, leading to the evacuation of coastal areas. In the United States and China, record-breaking temperatures exceeding 50°C have already been recorded. So-called "heat domes" and a "double jet stream" phenomenon are to blame. Our Science Editor Julia Sieger tells us more.