Quick summary: Ahead of the upcoming tournament across North America, emergency training experts have warned that heat related illnesses pose a critical and preventable danger to international athletes and spectators exposed to extreme summer temperatures. While conditions range from mild muscle spasms to life-threatening heatstroke, the bodily risk is often compounded by crowded environments, poor acclimatisation, and an incorrect reliance on plain water without vital electrolyte replacement. These urgent insights carry significant implications for public policy and healthcare practice, demonstrating that the rigorous implementation of specialized cooling strategies and localized heat stress monitoring is essential to safeguard the physiological well-being of tens of thousands of visiting football fans.
As temperatures climb across North America ahead of the 2026 FIFA World Cup, an expert has warned that heat-related illness poses a real and preventable danger to athletes and fans alike.
Owena Cleary, Director of CPR First Aid Training, has outlined the key differences between heat cramps, heat exhaustion, and heatstroke, detailing the warning signs to watch for and offering practical advice for fans, players, and members of the public facing a hot summer.
The 3 types of heat-related illness
Heat cramps are the mildest form of heat illness, presenting as painful muscle spasms usually in the legs or abdomen, caused by fluid and electrolyte loss through sweating. A person experiencing heat cramps remains alert with a normal body temperature and should seek shade, rest, and drink something with electrolytes.
Heat exhaustion occurs when the body can no longer regulate its temperature. It can cause a rise in temperature to 104°F, and the affected person may appear confused or feel faint. Other symptoms include heavy sweating, clammy skin, nausea, headache, and dizziness. The person should be moved to a cool environment immediately, laid down with legs slightly elevated, and given water if still conscious. If symptoms do not improve, emergency services should be called.
Heatstroke must be treated as a medical emergency. Body temperature can rise above 104°F, and without prompt treatment, heatstroke can cause organ failure and be fatal. There are two forms: classic heatstroke, which typically affects older adults, young children, or those with underlying health conditions during prolonged heat exposure; and exertional heatstroke, which occurs in otherwise healthy people during intense physical activity in the heat, making it especially relevant to athletes.
During heatstroke, a person’s skin will be hot and red. In classic heatstroke, sweating may be absent entirely. Other signs include nausea, confusion, slurred speech, and seizures. Emergency services should be called immediately. While waiting for help, bystanders should apply ice packs to the neck, armpits, and groin, fan the person while misting them with cool water, and immerse them in cool water if possible.
Hydration, clothing, and sun protection
Cleary notes that hydration is widely understood as critical to heat safety but is often misunderstood in practice. “During prolonged or intense activity in hot conditions, drinking excessive amounts of plain water without replacing sodium can, in rare cases, contribute to hyponatremia, a condition in which blood sodium levels become dangerously low,” she said. For activities lasting more than an hour, particularly when sweating heavily, electrolytes must be replaced alongside fluids. Options include sports drinks, coconut water, electrolyte solutions, and sodium-containing foods.
Clothing choice also affects how the body handles heat. Loose-fitting, light-coloured garments reflect solar radiation rather than absorbing it. Synthetic moisture-wicking fabrics can help, though in dry heat a loose cotton or linen layer may be more effective by trapping cooler air against the skin. Wearing sunscreen not only reduces the risk of burns and skin cancer but also supports the body’s ability to cool itself, as sunburn reduces the skin’s capacity to shed heat.
Alcohol should be consumed cautiously in hot conditions, as it is a diuretic and impairs the body’s ability to detect overheating. Exposure during the hottest part of the day, typically between 11am and 3pm, should also be avoided where possible.
Advice for World Cup athletes and coaches
The World Cup will be played across 16 host cities in the US, Canada, and Mexico, including Miami, Dallas, and Los Angeles, during some of those cities’ hottest months.
Visitors arriving from cooler climates should be aware that the body takes 10–14 days to acclimatise to heat. Exerting oneself heavily on arrival significantly raises the risk of heat illness.
Athletes can reduce their risk by training at the same time of day as competition, using pre-cooling strategies such as ice vests or crushed-ice drinks before kick-off, and following personalised hydration plans based on sweat-rate testing rather than thirst alone. Coaches should use cooling breaks and learn to distinguish heat illness symptoms, including cramping, confusion, disorientation, and absence of sweating, from normal fatigue. Heat stress should be assessed using the Wet Bulb Globe Temperature, which accounts for humidity and radiant heat as well as air temperature, and is considered the most accurate measure of heat stress.
What fans attending matches should know
Being in a crowd generates more heat than normal. Fans attending matches should check the heat index and humidity levels beforehand, eat before arriving, and carry more water than they expect to need. Wearing light colours is advisable, though those in dark team jerseys should consider a lighter underlayer.
Other practical steps include wetting the wrists and neck with cool water, alternating alcoholic drinks with a full glass of water, and locating the first aid tent upon arrival.
Fans should also keep an eye on those around them, particularly elderly attendees and children. “Watch for the quiet signs,” Cleary advises. “Someone who has gone quiet, stopped engaging with the game, or is sitting very still when they were previously animated may be experiencing early heat exhaustion rather than just tiredness.”
Research shows that heat acclimatisation and proper monitoring using tools like Wet Bulb Globe Temperature can substantially lower risks during major sporting events held in hot conditions. With the tournament expected to draw tens of thousands of international visitors, awareness of heat safety measures remains essential for participants and spectators alike.