July 21, 2022: -A nuclear power plant in Switzerland is reducing its output to prevent the river that cools it from which it hits temperature levels dangerous to marine life. This is the most delinquent example of Europe’s current heatwave having wide-reaching effects.

On Monday, the Swiss Broadcasting Corporation’s international unit, citing the public broadcaster SRF, told the Beznau nuclear power plant had “temporarily scaled back operations” to stop the temperature of the river Aare from increasing “to levels that are dangerous for fish.”

The Beznau plant includes two light water reactors producing roughly 6,000-gigawatt electricity annually. Plant operator Axpo says this “corresponds to around twice the electricity consumption of the city of Zurich.”

Instead of a cooling tower to regulate temperatures, the Beznau facility uses the River Aare. The planet warms this water through its operations, which is eventually funneled back to the river.

According to Axpo, the plant heats the water by 0.7 to 1 degree Celsius when it’s in “full load operation,” relying on water requirements. With Switzerland experiencing high temperatures, the decision has been taken to reduce output.

In a statement sent to CNBC through email, a spokesperson for Axpo said there were “regulations regarding water protection, which restrict the operation of the Beznau nuclear power plant at high water temperatures in the Aare.”

The spokesperson further said that Axpo attached to these requirements. “We are currently monitoring the situation on an ongoing basis and have already taken initial measures,” they said.

The output of the Beznau plant was, the spokesperson said, “regulated during the day depending on the current temperature of the Aare so that the requirements are met at all times.”

“This is a routine process that becomes necessary from time to time during the hot summer days,” they counted. “Due to the heat, we assume that further power reductions will be required over the following few days.”

The news out of Switzerland comes as parts of Europe grapple with a significant heatwave that has caused wildfires, pauses in travel, and death. The previous Friday, the U.K. issued a “Red Extreme” heat warning for this week.