How European teams are trying to beat the World Cup heat - ESPN

The heat hits immediately. You think you know what's coming, but it's still a shock to the system. Sweat appears almost instantly. The first deep breath is like sucking in hot air that feels like it's being pumped out of a hair dryer.

This is the reality for some of the players at this summer's World Cup in North America.

In a specially built lab on the south coast of England, Precision Fuel and Hydration can recreate the conditions teams are facing at some venues during the tournament. In an attempt to understand what it's like, I ran for 30 minutes and walked uphill for another 20 — roughly one half of a 90-plus minute football match — in conditions designed to match those in Miami or Monterrey, Mexico.

At nowhere near the same intensity of professional footballers, there's still an overall drop in body weight of 0.64% during 50 minutes of exercise. Core body temperature rises by 1.55 degrees Celcius. From those numbers, it's estimated that physical performance capacity has dropped by 10% in less than an hour.

Face, hands and feet are still burning long after the workout has finished. Fortunately, in this instance, that's the end of it, but players at the World Cup don't have that luxury. With games every few days, the final whistle is when attention turns to recovering as quickly as possible to do it again.

Playing conditions are measured by Wet Bulb Globe Temperature (WBGT) — a gauge of heat stress that accounts for air temperature, humidity, wind speed and solar radiation. At 28 degrees Celsius WBGT — the conditions in the heat lab — FIFPRO, the players' union, recommends that a game be postponed.

It's not a perfect science, but according to Precision Fuel and Hydration, modelling of the climate during this summer's