Club World Cup winners team who handles weather best: Dortmund's Kovac

The German side face Korean outfit Ulsan HD on Wednesday, looking to qualify for the last 16 from Group F in Cincinnati, where temperatures are set to reach 34 degrees Celsius.

"I think that this tournament will be decided not by the best team, but the team that can adapt to these weather conditions the best, and they will probably win this tournament," Kovac told reporters at the TQL Stadium.

Dortmund edged South African side Mamelodi Sundowns 4-3 at the same stadium on Saturday, in which their substitutes hid from the sun in the dressing room in the first half, and then under umbrellas pitch-side in the second.

"Our boys are very well taken care of by our doctors and the medical staff," continued Kovac. "We took the necessary measures and we try to do everything possible to make the right decisions and to take care of our players.

"We have very cold towels. We put them in ice baths. The boys also need to cool down their legs and feet in cold water and ice baths.

"During the last match, some of the boys watched the match from the dressing room. We didn't want them sitting on the bench in the direct sunlight. We want to keep them in the shade."

Kovac also said he did not want Dortmund's players to get too cold either. "We try to decrease the intensity of the air conditioning and the fans because it is very dangerous to go from hot to cold all the time," he added.

Kovac said winger Jamie Gittens, who has been heavily linked with a move to Chelsea, was not available to face Mamelodi Sundowns because he was ill.

"There were so many rumours at the moment, but he is actually sick," said Kovac. "He felt under the weather for the last couple of days with a clogged nose and a scratchy throat. You know, because if you are in the air-conditioned room all the time, you get sick, but it's part of the game."