Severe heat across Europe is forcing some nuclear and thermal power plants to reduce output or shut units because rivers used for cooling have become too warm or too low. Restrictions have affected facilities in several countries, including France and parts of central and eastern Europe, just as electricity demand rises for cooling. The disruption shows how prolonged heat can pressure grids from both sides: increasing demand while limiting thermal generation. Operators and grid managers are adjusting production and cross-border supplies to maintain system stability.