Soaring temperatures and oppressive humidity at the Club World Cup are fuelling concerns among players, coaches and fans, with calls for additional cooling breaks and adjustments to match schedules.
Midday kickoff temperatures in Pasadena at the weekend approached 32 degrees Celsius, forcing players in the Paris St Germain v Atletico Madrid match to dig in early as the midday sun blazed on the Rose Bowl's uncovered stands and pitch.
Atletico's Marcos Llorente described the conditions as "terribly hot," saying "my toes were sore, my nails were hurting... it's incredible."
Fans, too, voiced concern.
Attendees at the Rose Bowl complained of long queues in harsh heat, limited shaded areas and water restrictions at entry, with some leaving at halftime due to dehydration and fear of fainting.
Similar mid-afternoon kickoff conditions are planned for upcoming matches, stoking safety concerns for supporters and players.
Monday’s match in Pasadena was not an isolated incident.
Miami and Los Angeles are experiencing temperatures north of 30°C, many rising above the 32°C heat stress threshold, triggering warnings from player unions.
Tuesday's game between Real Madrid and Al Hilal is scheduled at 3pm local time with temperatures expected to reach 32°C with humidity set to hover around 70 per cent.
The world players' union FIFPRO has suggested Fifa should revise scheduling, if needed.
"FIFPRO has consistently advocated for comprehensive heat protection measures including mandatory cooling breaks, adjustments to kick-off times to avoid the most intense heat, and the postponement of matches when conditions pose a serious health risk to players," FIFPRO said.
"With tournaments like the Club World Cup featuring dense match schedules and hot climates in locations such as Orlando and Miami, extreme heat is becoming an increasingly important health and safety issue in professional football.
"FIFPRO will closely monitor the situation in the coming weeks with a view to prioritising player welfare over other considerations."
The current rules permit one mandatory break per half.
England coach Thomas Tuchel, observing the tournament as part of planning for next year's World Cup in North America, warned the tournament schedule would resemble "suffering," with players battling harsh midday conditions.
The heat represents one of many controversies plaguing the expanded 32 team format.
FIFPRO and the PFA have launched legal action in Brussels, alleging Fifa overstepped by introducing an unsustainable four week calendar, risking player burnout.
Critics say the added fixtures, combined with sweltering heat, could severely strain player welfare.
Fifa, however, maintains that the extended summer fixtures align with the broader International Match Calendar and that existing protocols are sufficient.