As intense heatwaves grip the United Kingdom, Spain, France and Portugal—at times exceeding temperatures of 40 C—as well as parts of North America and Asia, lakes around the world are feeling the heat from climate change, which is creating a cascade of ecological and environmental issues.

“Although a ‘longer summer’ may be welcome to many cottagers and campers, such weather conditions increase the risk of algal blooms, and especially cyanobacterial blooms, which can have far-reaching ecological consequences and even make drinking water toxic”