The teams will meet Wednesday at the Arena da Amazonia in the Brazilian rainforest, and the team that can better cope with the hot and humid conditions will likely to be the one to leave town with three points - something both countries could really use after opening losses.
Both squads head into the game with injury concerns, but Croatia midfielder Luka Modric appears to be on the mend. For Cameroon, striker Samuel Eto'o missed two days of practice, putting him in doubt for a starting spot.
The Croatians lost 3-1 to Brazil on Thursday, but the game turned in the second half when referee Yuichi Nishimura awarded a soft penalty to Brazil when the score was 1-1.
Croatia coach Niko Kovac called it a ''shameful'' decision, but he soon moved on to thinking about the all-important game against Cameroon.
''What we have showed on the (field) was great,'' Kovac said. ''What I can see in players' eyes is their desire to make up for what we have lost in the opener.''
Cameroon lost its opening Group A match 1-0 to Mexico. Another loss for either the Cameroonians or the Croatians is likely to mean an early exit from this year's tournament.
Cameroon was the first African team to reach the quarterfinals at a World Cup, progressing that far in 1990 after beating defending champion Argentina in the opening match. But they headed to Brazil this year after a player bonus pay dispute, delaying their arrival in the South American country.
Off-field troubles aside, Cameroon coach Volker Finke is fixated on fixing what went wrong against Mexico.
''We will analyze this together because the match against Croatia is very important if we want to stay alive,'' said Finke, perhaps even understating how critical a win is with Brazil waiting in the final group match.
Besides worrying about an early exit, both teams will also be wary of playing in the heat of the Amazon.
Italy beat England 2-1 in the first match at the Arena da Amazonia on Saturday, but the coaches from both teams complained about the conditions after the match.
Italy coach Cesare Prandelli even said it was ''absurd'' that FIFA didn't call for official timeouts to be used to give players a chance to rest and rehydrate.
The early forecast for Wednesday calls for more of the same, with a high of about 30 degrees C (86 degrees F) expected.
FIFA uses the ''Wet Bulb Globe Temperature'' to determine when official breaks should be added, and says the WGBT must be above 32 C (90 F) for cooling breaks to be considered.
Unless it gets even hotter by the time the match rolls around, players on both sides can expect another tough match in the jungle.
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