Switzerland manager Ottmar Hitzfeld has criticised FIFA's decision to make his side play World Cup matches in tropical regions of Brazil this summer.
The Swiss will take on Honduras in Manaus in the Amazon rainforest before playing France in the heat and humidity of Salvador.
"In Salvador it's very hot, Manaus is much worse because you are playing in a humid, tropical climate, with 95% humidity, and a temperature between 30 and 40 Celsius," Hitzfeld told SWR Radio.
"I find it almost irresponsible that one has to play football in such a place, in the middle of the jungle, in the middle of the Amazon region."
The former Bayern Munich boss also believes that his side's group matches are being held too far apart, claiming that travelling will take its toll on his players.
"I think the commercial side has taken precedence and I am not in agreement with FIFA," he added. "Brazil is a big country and you have to fly for five hours from Salvador to Manaus and that is also a big strain for us.
"We have some meetings in the next few weeks with sport scientists, with doctors and physiotherapists, we have to assess this intensively and prepare ourselves accordingly."
Switzerland have been placed in Group E with Ecuador, France and Honduras.