Extreme heat conditions, with temperatures expected to reach 100F (38C) in several regions, have disrupted Fourth of July festivities across the United States, causing cancellations and closures of numerous events. Washington D.C., Philadelphia, New York City, and other cities were affected, including the cancellation of a parade in Washington D.C. and the temporary shutdown of the Great American State Fair due to multiple cases of heat-related illnesses. Over 165 million people are sweltering under record temperatures along the US East Coast and Midwest, according to the US National Weather Service. The heatwave is not only disrupting the holiday weekend but also affecting President Donald Trump's celebration marking America's 250th birthday and multiple World Cup matches taking place outdoors. As a precautionary measure, several events were cancelled due to the blistering heat, with Philadelphia's Salute to Independence Semiquincentennial Parade being one of the biggest casualties. The DC Fire and EMS Department treated several people for heat-related illnesses at various events, urging residents and visitors to take precautions if they are going to be out in the heat. The extreme heat is expected to continue through the weekend, with Philadelphia and Washington D.C. approaching their all-time record highs. Other concerns include severe thunderstorms on the northern plains, the Midwest, and across to the Great Lakes, which will bring a dramatic end to the heat with damaging hail, destructive winds, flash flooding, and even a few tornadoes.