Didier Deschamps has concerns over the conditions for France's FIFA World Cup last-16 clash with Nigeria in Brasilia on Monday.
France visit the Brazilian capital for the first time in the tournament, but the 1pm (local time) kick-off could see temperatures reach upwards of 30 degrees Celsius (86 degrees Fahrenheit).
With all of France's group stage matches beginning in the late afternoon and early evening, it will be a new experience for the squad.
And Deschamps - who won the tournament as a player in 1998 - admits the sweltering conditions could cause problems.
"Yes, the heat worries me," he said in a press conference on Sunday.
"The match is at a different time so over the last three days we have been trying to adapt to this schedule by changing our food.
"You need to manage these problems. (On Saturday) we saw the Brazilians and Chileans after their match finished and they were very tired."
Deschamps has a fitness concern over defender Mamadou Sakho, who tweaked a hamstring in the 0-0 draw with Ecuador on Wednesday.
"He only ran in training on Saturday," he said.
"I'll see on Sunday night if he is available."comments