Legionella are rod-shaped bacteria that live in water and multiply there accordingly. According to a recent study by the Helmholtz Centre for Infection Research (HZI) in Braunschweig, the pathogens multiply not only at the previously assumed 25 to 45°C, but also at temperatures between 50°C u. 60°C. If you have an intact immune system and drink Legionella contaminated water, the risk of contracting the disease is very low. But things look different when it comes to showering at the latest. Respirable Legionella aerosols can be inhaled via the fine water mist produced during showering. These cause long-term damage and can cause serious infections such as legionellosis (pneumonia). In Germany alone, about 3,000 people die each year as a result of legionellosis. By comparison, there were around 3,200 traffic fatalities in Germany in 2017.