FIFPRO, the worldwide union for professional footballers, recorded that 19% of the tournament's matches were played at a wet bulb globe temperature (WBGT) of 28C or above, the level at which the union recommends postponing play, in data current to 16 July 1. WBGT measures more than the air: it folds heat, humidity, wind and radiant sun into a single index, so a small movement on it carries a much larger change in the physiological load a player is carrying. Nine matches, across the group stage and the knockouts, were flagged as played in severe heat.
Four degrees separate the two organisations. FIFA does not mandate cooling breaks until WBGT reaches 32C, while FIFPRO's threshold for stopping play altogether sits four degrees lower. Six venues were rated extremely high risk: Atlanta, Dallas, Houston, Kansas City, Miami and Monterrey. Talks on a written protocol have run since early July, with FIFPRO pressing for predetermined rules on delaying matches, rescheduling them or moving kick-off times rather than calls taken game by game 2. Afternoon kick-offs in a North American summer exist to reach European evening audiences, so a fixed medical threshold would take that decision out of the schedule's hands.
The medical argument now sits inside the argument about 2030. Gianni Infantino called the 48-team format a success and said 64 teams would be examined once the tournament finished ; Alejandro Dominguez, president of the South American Football Confederation (CONMEBOL), has pushed the same expansion on centenary grounds . FIFPRO opposes it on workload, projecting that elite internationals would face between 70 and 83 matches a season across club and country. Heat exposure scales with matches played, which turns a dispute about cooling breaks into a dispute about format.
