The threat of extreme weather has been a constant throughout the World Cup, which is being co-hosted by Mexico, Canada and the United States.<\/p>\n
Fifa introduced mandatory three-minute hydration breaks midway through each half for all World Cup fixtures because of the threat of high temperatures, though they have continued even in more comfortable conditions. <\/p>\n
Mexico have already experienced interruptions to their preparations so far this tournament, with their last-32 tie against Ecuador delayed by an hour because of thunder and lightning in Mexico City. <\/p>\n
The build-up to Sunday’s fixture has been dominated by talk about Mexico’s record at the Estadio Azteca and how England’s players will deal with the altitude. <\/p>\n
The arena sits 7,220ft (2,240m) above sea level, and Mexico have lost just twice in 89 matches at the iconic stadium.<\/p>\n
At that altitude, the Earth’s barometric pressure is lower, making the air thinner and meaning less oxygen is taken into the bloodstream with each breath.<\/p>\n
Even for professional footballers, that has a potentially significant impact – increased heart rate, shortness of breath, dehydration, quicker and more intense fatigue.<\/p>\n
The fixture had been set to start in the early evening, when temperatures were forecast to be about 20C.<\/p>\n
However, a midday kick-off is expected to see temperatures hit highs of about 23C, which will theoretically make conditions even more difficult. <\/p>\n