Football is a universal game. Of course if you push yourself beyond your limit, you will run yourself out. Its about conserving your energy. The local tournaments have matches when temperatures are high. I've played in that kind of weather. you have to slow yourself down a bit and change your style of play, conserve energy and monitor your body water.
And don't forget that the weather cools down quite a bit in the evening, the humidity and wind conditions also affect playing conditions so a lot of factors come in to play. The vuvuzelas were an interesting twist in the latest edition of the world cup. Those are all local factors that professional players should be able to acclimatize to.
Now the local teams would be able to adapt better to those conditions. But the teams from Europe for instance may find it harder to adapt. But that is only fair, because when a team from the Middle East goes to play in Russia for instance, they need to adapt to the biting cold which is less than ideal to them. There have been world cup football matches that have been played out in the snow. But if you are a professional, you just have to soldier on.