A “heat dome” formation is forecast to bring dangerously hot conditions across parts of the United States, with implications for World Cup fans and players. Multiple outlets report that the extreme weather pattern can cause prolonged periods of high temperatures and elevated humidity, leading to heat indexes in the range of about 40.5°C to 46.1°C over parts of the Midwest and East Coast. Under such conditions, heat stress becomes a risk, particularly for people spending extended time outdoors, exercising, or travelling between venues. The reports note that the heat dome is expected to affect a wide area, increasing the likelihood that match-related crowds and team activities could be exposed during peak afternoon and early evening hours. Local authorities and organisers typically advise hydration and heat-safety measures, though specific guidance can vary by venue and city. Overall, the reports converge on the message that the forecasted heat is severe enough to require careful monitoring and precautions to reduce the risk of heat-related illness.