AtlantaResearchers flagged 26 World Cup fixtures as dangerous.
The study found 1 in 4 of 104 games carry heat hazardous for athletes, concentrated in southern US host cities.
FIFA has not announced schedule or venue changes; once venues are assigned, no formal mechanism exists for relocation.
Sources: Phys.org
THE WET-BULB THRESHOLD
Heat danger for athletes is measured by wet-bulb globe temperature (WBGT), not air temperature alone. WBGT combines heat, humidity, wind, and solar radiation into a single number. Above 28°C WBGT, FIFA protocols mandate cooling breaks; above 32°C, outdoor endurance sport becomes medically dangerous regardless of fitness.
WHY HUMIDITY KILLS
The human body sheds heat primarily through sweat evaporation. When ambient humidity rises above roughly 75%, sweat stops evaporating efficiently — it just drips. Core temperature climbs even at rest. An athlete generating 1000 watts of metabolic heat in humid conditions can reach heatstroke territory within 30 minutes.
THE 1994 PRECEDENT
The last US-hosted World Cup played noon kickoffs in Dallas and Orlando to suit European TV schedules. Players described conditions as the worst they had encountered; the Italy-Norway match was played at WBGT levels that would breach modern protocols. FIFA learned little — 2026 group stage kickoffs are again scheduled for midday in the same southern cities.
THE STADIUM SOLUTION
Five 2026 venues have roofs or air conditioning — Atlanta, Dallas, Houston, Vancouver, and Los Angeles (SoFi). The other 11 are open-air. Qatar 2022 solved heat with stadium-scale air conditioning powered by solar farms, but those venues were purpose-built; retrofitting NFL stadiums for World Cup heat is not on FIFA's agenda.
WHAT ATHLETES ACTUALLY RISK
Exertional heatstroke kills via multi-organ failure, not heat itself. Core temperature above 40°C for more than 30 minutes denatures proteins in the gut lining; bacteria leak into the bloodstream; sepsis follows. Survival depends on cold-water immersion within minutes — a treatment most football medical bags cannot deliver pitchside.
WHY FIFA WON'T MOVE GAMES
World Cup broadcast contracts are signed years in advance with kickoff windows pinned to European prime time. A Dallas 3pm local kickoff is 10pm in Berlin — the value-maximizing slot. Moving games to evening kickoffs costs FIFA roughly $200m per round in renegotiated broadcast value. The athletes' risk does not appear on that ledger.