As the heat wave swept across France and gained momentum in the south this weekend, its effects were clearly visible on the jerseys of the riders who headed to Vaujany to complete stage 7 of the Criterium du Dauphiné. Black, blue, red, and yellow panels were interspersed with cracked white.

The salt stuck to the lycra was the remnants of the day's sweat. The amount of sweat was not half bad, as two high elevation passes and a sharp summit finish, all of which took place in temperatures over 30 degrees Celsius.

The heat colored not only the jerseys, but also the race. Stage winner Carlos Verona didn't seem to mind, nor did Primoš Roglic, who took the yellow jersey in a late attack from the group of favorites. However, it certainly put a damper on the rest of the field.

"To be honest, I was a bit on fire in the sunshine," said Tao Geoghegan Hart (Ineos Grenadiers).

The Englishman came here without much leg training or preparation, but still finished ninth in the stage and moved up to fourth overall. But if the temperature had been 10 degrees cooler, it probably would have been a different story.

"I felt like I had more legs, but my system was overheating. 'It's a shame, because I could have reacted to the attack. For the next two kilometers I ran the same pace as them.

"This morning DS said the temperature was 24 degrees on the bus, but at one point it got up to 36 degrees. I could train, but I couldn't imagine racing the Tour of Norway in 2 degree temperatures. But I'll be fine. That's life. Tomorrow is another day."

Another rider basking in the sun was Movistar's Matteo Jorgenson, who, like Geoghegan Hart, is fair-skinned and freckled.

"My genetics are basically heat-sensitive," Jorgenson said. 'My ancestors probably came from the north and are used to the cold. My body overcompensates when it's hot."

He experienced a similar phenomenon, although he fell before Geoghegan Hart. He did not explode, but his pace did not change.

"I was actually feeling pretty good all day until the last climb. Just that heat. My heart rate started to rise and I couldn't keep up. I swerved and gave it my all."

Jorgenson, who finished 14th in the stage and held eighth overall, was not caught off guard by the heat. In fact, he has thoroughly addressed the heat.

"I've been doing scientific research for the last few months. I end up sweating a great deal. I lose a lot of water and a lot of salt in that water, so it's kind of a double whammy," he explained. [I drink several bottles an hour, and I take a salt pill every hour, and I try to get between 1,300 and 1,700 milligrams, or at least a gram of salt an hour. That seems to help. I didn't drink enough water today, but that's complicated."

Similar temperatures are expected on Sunday, and the heatwave won't be over anytime soon. The terrain will not be easy either. Sunday's final stage's mid-stage climb may not be as high as Saturday's Galibier or Croix de Fer, but the summit finish on the Solaison Plateau is a different story than the short hike to Vaujany.

Ominously for Jumbo-Visma's rivals, second-placed Vingegaard revealed: "Both Primosch and I are good in the heat.