With several 2026 World Cup matches set to be played in hot conditions, we asked Dr Matt Maley, an expert in Environmental Physiology and Ergonomics, what the heat could mean for England's players and their chances of success:
Q: How do the temperatures expected at World Cup venues compare to those that England players are used to training in?
“Temperatures across the USA venues are quite variable. England's first game will be held in an air-conditioned stadium, with air temperatures typically around 22°C and with a covered roof. Solar load from direct sunlight won't be a concern”, said Dr Maley.
“Later group games move to open stadiums where temperatures rise to around 25–26°C, and the absence of a roof means players will also face additional heat stress from solar radiation.
“By contrast, England play their domestic matches through late summer into spring, where air temperatures typically range from around 5°C to 18°C so the step up in heat stress at this tournament is considerable.”
Q: How might the temperatures in the US affect England players' performance? What about recovery?
“Players performing high-intensity work in the heat will see a reduction in performance compared to what they're capable of in the cooler conditions they're used to at home.
“Recovery between matches can also be adversely affected; time spent in the heat increases fatigue and reduces comfort.
“Sleep quality may suffer too, particularly if hotel accommodation isn't properly air-conditioned (or switched on!).”
Q: What happens to the body when exercising in hot conditions? Is there a temperature at which performance begins to noticeably decline?
“When exercising in the heat, heart rate is elevated compared to the same effort in cool conditions meaning cardiovascular capacity is substantially reduced”, explains Dr Maley.
“Deep body (core) temperature rises more steeply too, and in players who aren't acclimatised, this can produce symptoms such as nausea and dizziness.
“Sweat rates are also considerably higher, leading to fluid and electrolyte losses that can further impair recovery between matches.
“In terms of thresholds, we start to see meaningful performance decrements at a Wet-Bulb Globe Temperature (WBGT) of around 26 °C, though this varies with the intensity of the exercise and the individual player.”
Q: Beyond temperature, are there any other weather factors that might be an issue?
“Absolutely. High humidity reduces the body's ability to cool itself by limiting evaporation of sweat from the skin. Solar radiation adds heat energy directly to the body, raising skin and core temperature.
“We typically use an index called the Wet-Bulb Globe Temperature (WBGT), which captures the combined effects of air temperature, humidity, and radiation in a single value.
“Sports organisations and governing bodies often use WBGT thresholds to determine when to implement rest breaks or, postpone events altogether.”
Q: Could teams from countries that regularly train in hotter climates have an advantage?
“Yes, potentially. People who live and train in warmer climates tend to be naturally acclimatised to exercising in the heat.
“England players, by contrast, if not prepared, will arrive without that adaptation, which means the heat will place a greater physiological strain on them.”
Q: How will teams such as England have been preparing for these conditions, and what strategies are typically used to adapt to heat?
“England's players will almost certainly have undergone a structured heat acclimation protocol either before travelling to the USA or shortly after arriving.
“This typically involves exercising in hot conditions for around 10 consecutive days.
“The adaptations this produces are well-documented: increased sweat rate, lower resting and exercising core temperature, and a reduced heart rate for the same workload. All of these translate directly into better performance and safety in the heat.”
Q: How much difference can factors such as kick-off time and match scheduling make to player performance and welfare?
“Kick-off time can make a substantial difference”, said Dr Maley.
“A mid-afternoon game will typically coincide with peak air temperature and the highest solar load of the day, maximising heat stress on the players. Evening kick-offs offer considerably more favourable conditions.”
Q: Are there particular player positions that are likely to be affected more than others?
“Midfielders typically cover the greatest distances in a match, around 10 km, so we'd expect that to drop in hot conditions as the body prioritises managing heat over sustaining high-intensity output.
“Wingers and forwards who rely on explosive speed may see a reduction in the number of sprints they produce, though peak sprint speed is generally better preserved than endurance-based running.”
Q: Could the heat influence tactics or the style of football teams play?
“Quite possibly. High-tempo styles of play are metabolically very demanding and generate a lot of body heat; those approaches are harder to sustain when ambient conditions are already hot.
“We may see teams adapt tactically, whether consciously or simply as a reflection of human physiological limits. Slower, more possession-based football may become more prevalent on the hottest match days.”
Media wishing to arrange an interview with Dr Matt Maley should email publicrelations@lboro.ac.uk
Related reading: 91²Ö¿â's physiology experts have been helping England match official Stuart Burt acclimatise to the heat ahead of the 2026 FIFA World Cup. Read more about his preparation.
