England's World Cup last-16 clash with Mexico at the Azteca Stadium on Monday morning promises to be one of the most demanding fixtures in recent football history — not because of the opposition's quality alone, but because of where the match is being played.

The iconic Azteca Stadium sits more than 7,000 feet above sea level, roughly one-and-a-half times the height of Ben Nevis, the United Kingdom's highest peak. At that altitude, the body absorbs less oxygen, heart rates climb faster, and fatigue sets in far sooner than at sea level. Even the flight of the ball changes in the thinner air.

Tuchel's own admission

England manager Thomas Tuchel has been candid about the scale of the challenge. "My understanding is we cannot adapt to the altitude," he said following England's victory over DR Congo. "It's a huge advantage Mexico will have. We have three days in between the matches and we cannot adapt to it. We knew that before. It's just a disadvantage for which we will have to deal with."

Tuchel did point to one area where his squad has prepared well. "We came very early to the country and to the US — we banked good heat training into our bodies," he said. "The players have lots and lots of heat training which will help them. The heat and humidity is not the problem. We are used to that."

Altitude cannot be mastered in days

Former England international Sol Campbell underlined just how unforgiving altitude can be on short notice. "You have to really judge it right in altitude — it's really hard on the body physically," Campbell told Sky Sports News. "It's great if you're there for two weeks, you're flying. But if you're parachuted in there, you have to time it right. It can sap a lot out of you."

Pundit Paul Merson was even blunter in his assessment. "If this was played anywhere else, England would win this football match," he told Sky Sports. "No Mexico player gets in the England team — we're by far the better team. But altitude at 7,000 feet? It's mind-blowing. England can't do anything. It takes a couple of weeks to get acclimatised. That is the biggest, biggest obstacle for England."

Mexico's fortress record

Mexico's record at the Azteca only deepens England's concern. In 89 competitive matches at their national stadium, Mexico have lost just twice and have remained unbeaten for 13 years. No World Cup side has beaten them there in 10 attempts. The co-hosts have also already played three matches at the Azteca during this tournament — group-stage wins over South Africa and Czech Republic, and a last-32 victory over Ecuador — meaning the conditions hold no mystery for them whatsoever.

England's last visit to the Azteca came at the 1986 World Cup quarter-final against Argentina, a game remembered for Diego Maradona's 'Hand of God' goal. That match was also played at altitude above 7,000 feet. More recently, England played two matches above 4,000 feet at the 2010 World Cup in South Africa — against the United States and Germany — and failed to win either game, despite Fabio Capello's side completing a high-altitude training camp beforehand.

Kane's rallying call

Captain Harry Kane, whose goals against DR Congo booked England's passage to the last 16, acknowledged the enormity of what lies ahead. "Mexico in Mexico is as big as it gets in the World Cup," Kane said. "The atmosphere is going to be incredible and tough for many different reasons. If you want to be world champions, you have to go through tough games."

England possess the individual quality to cause Mexico serious problems — but first they must survive the mountain.