Thermal pollution is a hazardous rise in temperature in lakes, rivers, oceans, ponds, streams, and other bodies of water caused by industrially discharged water. This industrially discharged water is heated. Heating the water of an area lowers the ability of oxygen to dissolve into the water, meaning it's harder for the aquatic life there to breathe, and it makes it easier for the wildlife to catch diseases.

Thermal pollution is when manmade waste products put into a river, lake, or stream cause a rise in water temperature that dramatically affects the ecosystem.