Lightning kills around 25,000 people every year, and injures ten times that number. But what exact damage does it cause to the body? What does it do to the heart, and what constitutes a deadly dose of current?The researcher Irina Munteanu at TU Darmstadt has now developed a computer program that can simulate what happens when someone is hit by lightning. It allows a realistic prediction of how the electricity spreads through the body, and in the process is also helping to improve safety in cars and buildings.