FWIW plants with cooler towers are not really affected by the heat wave, as an other comment notes the issue is for plants next to intermediate bodies of water (in France that's mostly plants on the Rhone which is a pretty large river): since they were next to a pretty big body of water they were designed without cooling towers, but the combination of warming & body of water not being quite big enough it's possible for the water flow & temperatures to adversely effect cooling and thus require throttling.