A police motorcyclist was taken to hospital after a collision, Richie Porte was unwell and Nathan Haas questioned whether they should have raced at all.
Even at a race well-known for hot conditions, Friday's blast furnace made it a tough day in the Tour Down Under.
World champion Peter Sagan won the 128.2km fourth stage from suburban Norwood to Uraidla in the Adelaide Hills.
The temperature hit the mid-40s, prompting Tour organisers to start the stage an hour early.
A mass participation ride scheduled for earlier in the morning, taking the same route as stage four, was also cancelled.
As the temperature soared, the police motorcyclist collided with a car at Gumeracha in the hills and was taken to hospital with non-life threatening injuries.
Porte, the defending champion, finished in the lead bunch and remains a key contender ahead of Saturday's decisive Willunga stage.
But he later revealed he was not feeling well.
"Just a bit of tummy ... it could be the heat, it plays havoc on your body," he said.
Haas was the big loser on stage four, struggling on the Norton Summit climb near the end of the stage and finishing 54 seconds adrift of the front group.
"I don't want to sound like a sore loser, but we shouldn't be racing in conditions like that - in my opinion. It's just upsetting," Haas told the cyclingnews website.
"The guys who won, they handled the heat and people can say 'Nathan you're exaggerating here' but it's not safe to do this.
""Hats off to the guys who can suffer more than me but I didn't actually know I was in a bike race in the end ... I didn't know where I was."
Share
