Great Britain's energy system operator has raised concerns that power supplies will face strain Thursday evening as extreme heat drives households to turn on fans and air conditioning equipment. The warning follows a similar call for extra generation just weeks earlier, during a June heatwave that broke seasonal temperature records, and occurs as the nation enters its third sustained hot period within the year.

The challenge reaches beyond British shores, with French nuclear reactors reducing output due to insufficient river water for cooling systems—a concern because these plants normally export electricity to the UK and neighbouring countries. Although grid officials have stated there is no genuine risk to household power supplies, the recurring warnings highlight growing pressure on energy infrastructure during extended periods of elevated temperatures expected to persist over several days.