Ten Juventus players asked to be substituted during the Club World Cup defeat by Real Madrid, says manager Igor Tudor.

The last-16 game on Tuesday was played in hot and humid conditions in Miami, with the temperature reaching 30C and humidity 70%.

Up to five substitutions are permitted during a game, and up to six if it goes to extra time.

Gonzalo Garcia's goal gave Real a 1-0 victory in normal time and Tudor made the maximum five changes allowed at Hard Rock Stadium.

"In the end, 10 players asked to be substituted," he said. "The exhaustion was incredible.

"There's the tension of this match, which burns your energy. Then there's this heat, which really gets to you, and the third thing that completes the conditions is playing in this humidity."

Extreme heat in the US has affected many games during the Club World Cup, with Borussia Dortmund manager Niko Kovac saying he was "sweating like I've just come out of a sauna" during his side's group win over Mamelodi Sundowns in Cincinnati, Ohio.

The temperature reached 36C during Benfica's group win over Bayern Munich in Charlotte, North Carolina, while Chelsea manager Enzo Maresca said it was "impossible" to organise normal training sessions amid a "code red" severe heat warning in Philadelphia.

'Cooling breaks' are mandatory once certain conditions are reached and they have been implemented in 33 out of 56 matches.

Fifa guidelines currently rely on the wet bulb globe temperature (WBGT), a measure of heat stress combining temperature and humidity.

If the WBGT exceeds 32C, cooling breaks are mandatory in both halves of a match.

Global players' union Fifpro has said breaks should be introduced once the WBGT goes above 28C, and matches should be delayed if it exceeds 32C.

The US will host next year's World Cup.

A leading specialist on the effects of extreme temperature on the human body told BBC Sport this week that Fifa should consider starting the final at 9am local time should there be similar conditions to those at the Club World Cup.