European teams say they are more prepared than ever for a hot and humid World Cup, training in saunas, planning to soak their jerseys in cold water before games and working with doctors to design the perfect hydration formula for each player.
Even though the tournament is held in Brazil's winter, stadiums in the tropical north will be warm, with temperatures often above 30 Celsius (85 Fahrenheit). And many games will be played under the afternoon sun, so they can be broadcast in prime time in Europe.
In the 1994 World Cup in the United States, many cold-weather teams wilted. Since then, teams have borrowed cooling techniques from the military and consulted with scientists to make sure they can keep the heat from corroding performance.
"There's lots of little things you can do that on their own wouldn't make a fundamental difference but they all add up," said Mike Tipton, a scientist at the University of Portsmouth who has been helping England coach Roy Hodgson.
Brazilian authorities generally avoid scheduling important domestic matches before 4 p.m. But FIFA scheduled 24 of the 64 World Cup games to start at 1 p.m., prompting some complaints from players' union FIFPro.
Matches in cooler southern cities, including Rio de Janeiro, venue for the July 13 final, should be fine. But results in sweat-box cities further north and Cuiaba in the west will depend not only on how fit the players are, but how well the teams doctors and consultants performed.
Italy coach Cesare Prandelli witnessed how destructive Brazilian conditions can be when eight of his players asked to be substituted at halftime of the Confederations Cup semifinal last June in the northern coastal city of Fortaleza, which is hosting six World Cup matches.
All of Italy's Group D games are in the north, starting with a sweaty encounter against England in the Amazon city of Manaus. To acclimatize them and measure how their bodies cope, Prandelli made players train on treadmills and bikes in a sauna heated to 33 Celsius (91 Fahrenheit) with 70-percent humidity.
"We've tried to reproduce the environmental conditions that we will likely find, above all in Manaus, but also in Recife and Natal," team physician Enrico Castellacci said. "Players work on a specific program and then we evaluate their resistance to the fatigue, by monitoring their heartbeat and weight before and after the exercises."
Players cooled off by plunging their hands into icy water. Tipton said that technique was first developed to cool navy firefighters and works better than soaking the whole body in ice baths or fancy gizmos like air-conditioned vests and jackets packed with dry ice.
In its manual on football medicine, FIFA says players' bodies need three days minimum, and ideally 14-21 days, to acclimatize to heat. Once that happens, they can cool more quickly and lose fewer minerals through sweat.
Some players acclimatize slower and less effectively than others. Smart coaches could be those who identify heat-susceptible players early and leave them off World Cup squads or on the bench for hot games. Doctors can analyze players' sweat to gauge how acclimatized they are and to tailor salt dosages in their rehydration drinks.
Players also must prepare mentally.
"Some just find it very oppressive and just can't play as well because they just can't handle it mentally," said Julien Periard, a specialist at Qatar's Aspetar sports medicine hospital. Research there included subjecting volunteers to an hour of 50-degree and then 48-degree temperatures (122 and 118 Fahrenheit).
"Some get quite aggressive at the end because they can't tolerate the heat," Periard said.
England made players wear three layers of clothing at a training camp in Portugal.
"Players need to learn to be comfortable being uncomfortable," said Hodgson.
Then coaching Switzerland, Hodgson experienced firsthand the baking heat of the 1994 World Cup. He likened Switzerland's opening match in Detroit's Pontiac Silverdome — which had no air conditioning — to "playing in a hot dog stand."
In Orlando, temperatures soared to 110 Fahrenheit (above 40 Celsius) when Ireland lost 2-1 to Mexico, prompting Ireland coach Jack Charlton to gripe: "The Mexicans didn't beat us, the weather did."
FIFA medical chief Michel D'Hooghe was so concerned about the health risks he pushed unsuccessfully for cooler kickoff times. Some players used special sun-reflecting hair gel. World Cup rules then didn't allow for drink breaks in extreme heat, as they do now.
"We thought we were being quite professional in our preparation but if you compare it with what we are doing now it was unbelievably amateurish," Hodgson told the Guardian newspaper.
Still, teams from cooler climes will still be disadvantaged in Brazil, likely forced to tailor their play to the heat, perhaps running less and passing more. This will be the eighth World Cup in the Americas. Only South American teams — Uruguay, Brazil or Argentina — won the previous seven.
"We've got very capable players for playing the kind of game played in places like Liverpool and Manchester," Tipton noted. "That doesn't translate to playing in a hot, humid environment where, over the years, you'll evolve a player who is much more skillful on the ball but unable to run about very much."
Cool-weather teams may "end up playing a game that they're just not used to," he said. "Teams who come from hot, humid environments will just be playing their natural game."
AP Sports Writer Andrew Dampf in Rome contributed. John Leicester is an international sports columnist for The Associated Press. Write to him at email@example.com or follow him at http://twitter.com/johnleicester