Germany is expecting potentially record-breaking temperatures on Tuesday, as several parts of the country raised their forest fire alarm to its highest level. German meteorologist Sabine Krüger said that the hottest areas are likely to be in western Germany, especially the low areas of the Rhine and the Ruhr. The highest temperature measured in Germany this year was 39.2 degrees Celsius in eastern Germany on June 19. While today's temperatures will not be confirmed until later in the evening, this year's record is likely under threat and the all-time highest temperature recorded in Germany - 41.2 degrees in June 2019 - may also be breached. German Health Minister Karl Lauterbach tweeted that "young people should take care of the elderly and remind them of the need to drink and keep cool," warning that the lives of elderly people will be in danger in the unusually high heat. In 10 of Germany's 16 states, predominately in the south, west and north-east, the highest of five alert stages for forest fires has been issued. The Bavarian forestry minister called on the public to take special care when walking through forests, warning that heat alone does not cause a fire, but that even an errant cigarette butt can ignite an inferno. On Monday, a forest fire erupted in a national park in the eastern German state of Saxony. While authorities declared that the fire was under control, they also warned of the risk of the flames reigniting. Another forest fire near the city of Essen in western Germany was brought under control by firefighters early on Tuesday. The affected area has been soaked with large quantities of water to prevent further fires. Dry conditions and high temperatures have created the perfect conditions for fires to ignite and spread quickly in many parts of Europe. The last week has seen numerous wildfires erupt in Croatia, France, Greece, Italy, Portugal and Spain, among others. The heat is causing problems across Europe. On Tuesday, parts of Britain's railway network were shut down due to high temperatures. The German national rail operator (DB) also said on Tuesday that "high temperatures can cause problems for the train tracks and the track bed, because steel can become flexible in extreme temperatures." DB is looking at methods of cooling sensitive parts of the trains and tracks, and is using sensors to monitor heat exposure. Germany's rivers are also under strain from the hot, dry weather. According to the German Federal Institute for Hydrology on Tuesday, two of the countries major rivers and shipping routes, the Elbe and the Rhine, currently have lower water levels than usual, sometimes forcing ships to lighten their load to avoid getting stuck.