Freshwater fish are suffocating in rivers across Europe during the heatwave.
In West Germany where temperatures have reached around 39 degree's celcius, there's hardly been any rain in the last few months, leaving the Rhine river in Cologne very low.
Germans and tourists as well as pets will have to be careful when thinking about taking a dip in rivers or lakes to cool off because of an increase of harmful bacteria and algae in stagnant waters.
Holger Sticht from the Environmental Protection Agency Bund says the extreme temperature is not great for the eco-system. "Lots of organisms will die out, you will see lots of dead fish and other creatures in the Rhine, shellfish for example. When it eventually rains again they will be able to re-colonise. But for the creatures living in the Rhine at the moment this is an absolute catastrophe."