Millions of Americans are experiencing a historic heatwave, forcing many July 4th celebrations to be canceled. A strong weather system has brought high temperatures and humidity to the eastern two-thirds of the country. In Washington, D.C., the Independence Day Parade was called off due to safety concerns. The Great American State Fair also had to close temporarily because of the dangerous heat. Around 160 million people are under heat warnings nationwide. A 'heat dome' is trapping hot air, causing temperatures to reach the upper 90s and low 100s Fahrenheit, feeling even hotter with the humidity. Many cities have broken daily heat records that have stood for over a century. Nighttime temperatures are also staying high, offering little relief. The extreme weather has led to the cancellation or delay of many parades and events, including fireworks displays. Even historical sites like Gettysburg National Military Park have moved outdoor programs inside. Transportation services, like Amtrak, have also been affected, with some trains running slower. Local governments are opening cooling centers and providing support to protect residents, especially the elderly and children. Sadly, at least one death has been reported due to the heat. The high demand for air conditioning has also caused electricity prices to increase significantly. Experts believe that climate change, caused by human activities, is making these heatwaves more intense.