Companies are reporting a drop in business, reflecting the economic toll of the heat wave, which is lowering productivity and keeping shoppers at bay.

The heat was so expansive that mountaintops, including the French Alps, that are usually frozen from snowpack saw record temperatures. Heat records were set for June in Spain and Portugal.

Four people died in Spain, two in France and two in Italy as an early summer heatwave continued to grip much of Europe on Wednesday, triggering health alerts and forest fires and forcing the closure of a nuclear reactor at a Swiss power plant.