2026 World Cup to Elevate Heat, Respiratory Disease, and Environmental Health Risks Across Host Nations

Mass gatherings amplify health risks through dense crowding, rapid international movement, and increasing demand on local infrastructure. These conditions increase transmission potential for infectious diseases while also elevating non-infectious risks such as heat stress, injury, and environmental exposure.

Public health coordination and preparedness activities are underway across all host cities, including planning for foodborne outbreaks, respiratory disease transmission, and heat-related illness. Post-pandemic assessments continue to highlight gaps in local public health capacity, particularly in understaffed and under-resourced jurisdictions.

Respiratory and Vaccine-Preventable Diseases

Respiratory infections are expected to be among the most common health events during the tournament. Enclosed and high-density environments such as stadiums, airports, hotels, fan zones, and public transport systems create favorable conditions for disease transmission.

Measles remains a major concern due to ongoing outbreaks across all three host nations and globally. Vaccination remains the most effective protection against infection and severe outcomes. Seasonal influenza and COVID-19 are also likely to circulate during the tournament.

Food- and Waterborne Diseases

Gastrointestinal illness is consistently among the most commonly reported health issues during mass gatherings. Risk is expected to be highest in Mexico due to variable sanitation standards and unsafe tap water in many areas. Pathogens of concern include norovirus, hepatitis A, and typhoid fever; traveler's diarrhea is likely to remain one of the leading causes of illness among international visitors. In Canada and the US, food and water safety standards are generally high; however, temporary surges in tourism demand may still contribute to sporadic foodborne illness clusters.

Vector-Borne Diseases

Mosquito-borne diseases, particularly dengue fever, are expected to pose a seasonal risk in parts of Mexico and the southern US during the summer months. Higher-risk areas include warmer, lower-altitude regions in Mexico and southern US states. Rainfall during the tournament period may further increase mosquito breeding activity in some regions.

Although large vector-borne disease outbreaks directly linked to sporting events are uncommon, imported infections among international travelers could contribute to localized transmission where competent mosquito vectors are present.

Crowd-Related Injuries and Sanitation Issues

Although uncommon, crowd surges remain among the most serious stadium-related safety risks. Modern stadium infrastructure and established crowd-management protocols significantly reduce these risks, though situational awareness remains important, particularly in fan zones, transport hubs, nightlife areas, and stadium entry or exit bottlenecks.

Increased alcohol and recreational drug consumption during large sporting events is also expected to contribute to higher rates of trauma, dehydration, interpersonal violence, and medical emergencies.  

Heat-Related Illness and Dehydration

Extreme heat is likely to represent the most significant and consistent health risk, particularly in southern US cities and parts of Mexico. Elevated temperatures substantially increase the risk of dehydration, heat exhaustion, and heat stroke, especially during prolonged outdoor exposure, alcohol consumption, or physical exertion. Vulnerable groups include older adults, children, and individuals with chronic medical conditions.

Preventive measures:

• Limit outdoor activity to cooler parts of the day (early morning or evening).

• Take frequent breaks and seek shade.

• Use air conditioning where possible or access public cooling centers.

• Stay well hydrated by drinking water regularly throughout the day.

• Avoid excessive intake of alcohol, caffeine, and sugary drinks.

Wildfire Smoke and Air Quality   

Wildfire season overlaps with the tournament period, particularly across western Canada and parts of the western and southern US. Smoke events may also affect parts of Mexico. Forecast climatic conditions for June and July are expected to support above-normal wildfire potential across portions of the northwestern and southern US, western Canada, and western Mexico.

Wildfire smoke can significantly degrade air quality, increasing respiratory and cardiovascular risks, particularly among individuals with asthma, chronic respiratory disease, or cardiovascular conditions. Travelers with pre-existing conditions should closely monitor local air quality advisories and reduce outdoor exposure.

Altitude-Related Illness in Mexico City

Mexico City, one of the tournament's highest-altitude host cities, sits at approximately 2,240 meters above sea level. Travelers arriving from lower elevations may experience symptoms of mild altitude sickness, including headache, nausea, shortness of breath, fatigue, and sleep disturbance. Symptoms typically resolve within 24-48 hours with acclimatization.   

Vaccinations

No specific vaccines are required for entry into Canada, Mexico, or the US.  However, all travelers should ensure they are up to date on routine immunizations, including measles-mumps-rubella (MMR), diphtheria-tetanus-pertussis, varicella (chickenpox), polio, pneumococcal, and influenza. Travelers should consider obtaining a COVID-19 vaccination where available. Additional vaccines to consider based on risk include: Hepatitis A (especially for Mexico); Hepatitis B; Rabies (for extended stays or animal exposure risk); and Typhoid (for higher-risk travel in Mexico).

Prescription Medications and Pharmaceutical Access

Travelers should anticipate significant variation in pharmaceutical regulations, medication availability, and enforcement standards across the host countries.

Travelers are advised to:

• Keep medicines in their original, labeled containers. Ensure that they are clearly labeled with your full name, the health care provider's name, the generic and brand name, and the exact dosage.

• Bring a copy of prescriptions and a physician's letter.

• Pack sufficient supply for the entire trip, plus contingency days for delays.

• Avoid purchasing medication from unregulated or informal vendors.

• Be aware that brand names and formulations may differ between countries.

• Check with the foreign embassy of each country you plan to visit or pass through for any prescription restrictions.    

The 2026 World Cup is expected to proceed without major public health disruption, although localized health incidents and environmental disruptions remain likely during the tournament period. Overall health risks to travelers are expected to remain manageable with appropriate preparation and preventive measures. Key protective measures include maintaining up-to-date vaccinations, following food and water precautions, implementing heat mitigation strategies, and monitoring environmental conditions such as wildfire smoke and air quality.

While the scale and operational complexity of the tournament will place pressure on public health systems across North America, coordinated surveillance, preparedness planning, and strong clinical infrastructure are expected to reduce the likelihood of widespread health emergencies. This report represents the latest data available as of May 22.

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