Football had a fierce reckoning with heat at the recently concluded FIFA Club World Cup in the United States, a sweltering preview of what players and fans may face when the US co-hosts the World Cup with Mexico and Canada next summer.

With temperatures rising worldwide, scientists warn that staging the World Cup and other soccer tournaments in the Northern Hemisphere summer is getting increasingly dangerous for both players and spectators. Some suggest that FIFA may have to consider adjusting the soccer calendar to reduce the risk of heat-related illnesses.

ESPN also noted that FIFPRO executives suggested canceling FIFA Club World Cup matches in Philadelphia due to the heat, as temperatures went beyond their threshold of 82.4 degrees on the WetBulb Globe Temperature gauge. According to WeatherSpark, the average temperature in Philadelphia for late June is around 87 degrees.

The FIFA Club World Cup is in the rearview, but it will provide a road map for Philadelphia planners putting on next year's World Cup matches. Why it matters: The 2026 event is expected to have a roughly $770 million economic impact on Philly,

The tournament delivered spectacle and a clear warning: hosting the world's biggest sporting event next summer will take more than world-class stadiums.

Real Madrid has won the most FIFA Club World Cups with five. Below are all the clubs who have won one title or more: