Extreme heat at the World Cup: Are FIFA’s safeguards enough?

On a midsummer day in Miami, temperatures can exceed 32°C with high humidity. Inside a packed stadium of 65,000 fans, conditions can feel several degrees hotter, creating a potential health risk for players on the field.

These are the kinds of environments teams may face at the 2026 FIFA World Cup, scheduled for June and July—typically the hottest months across much of North America.

FIFA has already recognized this risk and introduced mandatory cooling breaks in each half of every match for the first time in World Cup history.

But the question remains: is this enough to protect players from extreme heat?

It’s not just the temperature

Heat stress in sport is not determined by air temperature alone. What matters to the human body is a combination of heat, humidity, solar radiation, and airflow. These factors are often summarized using the wet-bulb globe temperature (WBGT) index, a metric developed in the 1950s to reduce heat illness during military training.

Soccer presents a unique challenge under high WBGT conditions. Elite players routinely cover 10 to 13 kilometers per match, repeatedly sprinting, decelerating, and changing direction. This generates substantial internal metabolic heat.

At the same time, opportunities for heat loss are limited. Uniforms, continuous play, limited shade, and restricted airflow reduce the body’s ability to cool itself effectively.

When heat production exceeds heat loss, core body temperature rises. This increases cardiovascular strain, raises perceived exertion, reduces performance, and elevates the risk of exertional heat illness. These conditions can range from muscle cramps and heat exhaustion to exertional heat stroke, a life-threatening medical emergency.

What forecasts show for 2026

Historical weather data across the 16 World Cup host cities suggest that heat stress will be common, particularly for afternoon kickoffs in cities such as Dallas, Houston, Miami, Kansas City, and Monterrey.

While some venues—including Dallas, Houston, and Atlanta—feature retractable roofs that can help regulate temperature and airflow, most matches will still be played in open-air stadiums, exposing players directly to environmental heat.

Later kickoffs may provide only limited relief, especially in humid locations where sweat evaporation is less effective.

Until recently, much of the evidence on heat strain in professional soccer came from controlled simulations. However, emerging field-based research measuring core temperature during actual professional matches provides a clearer picture of real-world conditions.

Findings indicate that during competitive match play:

Average peak core temperature often exceeds 39°C, rising steadily before halftime or full time

Players’ core temperatures can exceed 40°C in some cases, even under conditions not traditionally classified as extreme heat risk

This can occur even when cooling breaks are implemented

Importantly, these observations come from elite professional athletes who are highly fit and often acclimatized to warm conditions.

Taken together, the evidence suggests that elite soccer players can reach—and sometimes exceed—core temperatures of 40°C during matches played under what are already considered high-risk environmental conditions.

Are cooling breaks enough?

Cooling breaks are a practical and evidence-based intervention. FIFA’s decision to implement them universally at the World Cup is a proactive step in reducing heat strain.

When combined with strategies such as cold fluid intake and ice towels, cooling breaks can reduce the rate of core temperature increase, lower heart rate, and decrease perceived exertion, particularly in male players.

However, there are important limitations.

First, cooling breaks do not prevent significant rises in core temperature. They slow the increase but do not eliminate it. Players may still reach dangerously high internal temperatures even with structured cooling.

Second, emerging evidence suggests that cooling breaks may have different physiological effects in women’s soccer. Although women athletes generally reach lower absolute core temperatures than men, standard cooling break protocols appear to provide less relative reduction in physiological strain.

Research indicates that women may benefit more when cooling breaks are paired with longer halftime recovery periods in cooler, air-conditioned environments.

In short, while cooling breaks help, they are unlikely to be sufficient as a standalone solution.

What other sports are doing

Most heat policies in sport rely heavily on environmental measures such as WBGT thresholds. While useful, these metrics only describe weather conditions, not the actual physiological strain experienced by athletes.

Some sports are now shifting toward models that consider predicted changes in core body temperature, combining environmental data with sport-specific demands such as workload, clothing, and intensity.

This approach focuses on the body’s ability to maintain thermal balance through sweating and heat dissipation, rather than relying solely on external conditions.

For example, World Rugby has adopted heat guidelines tailored to the sport’s physical demands and uniform requirements. Similar approaches are also used in various recreational sports through organizations such as Sports Medicine Australia.

Timing matters—more than most realize

One of the most effective heat mitigation strategies requires no equipment or technology: scheduling matches outside the hottest part of the day.

Afternoon kickoffs consistently produce the highest thermal strain because they combine peak air temperatures with maximum solar radiation. Evening matches reduce—but do not eliminate—risk, particularly in humid climates.

From a player safety perspective, scheduling may be just as important as in-game cooling strategies. However, broadcast schedules have historically favored afternoon kickoff times for global viewership.

An ongoing challenge

Heat stress is already being reported more frequently in domestic leagues, international tournaments, and youth competitions.

As global temperatures continue to rise, heat policies in sport will need to evolve accordingly.

Protecting player health will require earlier decision-making, stronger mitigation strategies, and a willingness to reconsider not only how matches are played—but when they are played at all levels of the sport.