After a hot World Cup: a heat protocol for team-sport staff

The 2026 World Cup in North America turned heat stress from a sports-medicine topic into a headline. Before the tournament, a World Weather Attribution analysis estimated that around 26 matches would be played at a wet-bulb globe temperature (WBGT) of 26°C or more, against about 21 under the climate of the 1994 World Cup, and around five at 28°C or more, against three. FIFA introduced three-minute cooling breaks in each half. In July, reporting on a Guardian analysis found that nearly one in five matches had been played at heat levels the players' union FIFPRO considers high risk.

The thresholds at the centre of the argument were simple. FIFPRO recommends cooling breaks from 26°C WBGT and considering postponement above 28°C. FIFA's own reference point for cooling breaks has been 32°C.

Why this is not just a World Cup problem

Most team-sport athletes will never play a World Cup afternoon fixture in Kansas City. Many more will do pre-season in July, play academy tournaments in midsummer or train on artificial pitches at four in the afternoon because that is when the facility is free. Few clubs have shaded or air-conditioned venues, and the staff that plans the session is usually the same staff that would have to manage a collapsed player.

WBGT is the right number to watch because it combines air temperature with humidity and radiant heat. A 30°C day with high humidity and full sun can be far more demanding than the thermometer suggests.

What the IOC consensus recommends

The International Olympic Committee consensus statement on sport in the heat, published in the British Journal of Sports Medicine in 2023, remains the most complete reference. For athletes and their staff, its key points are:

• Heat acclimation is the main preparation. The preferred method is training in conditions similar to competition; 60 to 90 minutes a day for at least two weeks is described as optimal, but shorter exposures still produce useful adaptation.
• At least four heat sessions a week are recommended to induce acclimation and two a week to maintain it. Because adaptation decays more slowly than it develops, athletes can acclimate up to a month ahead and briefly re-acclimate in the days before competing.
• Hydration should be monitored with the weight, urine and thirst approach: daily body mass changes kept under 1 to 2%, urine specific gravity below 1.020, measured in the morning.
• Avoid hypohydration of more than 2% of body mass during training and competition in the heat, and build fluid intake over the preceding days rather than only on match day.
• Medical staff should be trained to recognise exertional heat stroke, confirm it with rectal temperature and apply rapid whole-body cooling on site: cool first, transport second.

In hot conditions, the session plan is a medical decision as much as a training one.

A practical heat protocol for a squad

Turning the consensus into routine does not need a laboratory. It needs decisions made before the hot day arrives:

• Set club thresholds in WBGT before the season, for example adopting FIFPRO's 26°C and 28°C levels, and decide in advance what changes at each level: session length, work-to-rest ratios, extra breaks, a move to early morning.
• Measure conditions at the pitch, not from a weather app for the city.
• Build a progressive heat block into pre-season, especially for players returning from cooler places.
• Weigh players before and after sessions to learn individual sweat losses, and check morning body mass and urine colour during hot spells.
• Have cold-water immersion ready on site during the hottest sessions and make sure everyone knows who is responsible for using it.
• Expect sessions in the heat to feel harder than planned, and read the internal load rather than assuming the drill costs what it did in spring.

The tournament also showed how quickly heat policy becomes a negotiation between schedules, broadcasters and medical advice. For a club staff, the advantage is that the decision is local. Nobody needs permission to move a session to 8 a.m.

In SquadStats, sessions are planned on the team calendar, and session RPE captures the internal cost of each one, including when heat makes it harder than prescribed. The next morning's wellness check-in (sleep, soreness, mood, stress, motivation) and readiness score show who has not recovered before the next hot session.

Sources

1. World Weather Attribution: Climate change big player at FIFA World Cup 2026 (May 2026)
2. Racinais S et al. IOC consensus statement on recommendations and regulations for sport events in the heat. British Journal of Sports Medicine, 2023
3. VitalLaw: Nearly one in five World Cup matches reached heat levels flagged by players' union (July 2026)
4. ESPN: FIFPRO concerned by US summer temperatures ahead of the 2026 World Cup (June 2025)