A massive heatwave, characterized by a weather phenomenon known as a "heat dome," is poised to engulf central and eastern regions of the United States this week. This meteorological event, formed by high pressure areas that act like a lid trapping hot air close to the ground, could result in temperatures reaching an oppressive 46 degrees Celsius (115 degrees Fahrenheit) ahead of Independence Day celebrations and World Cup matches in various U.S. cities. The National Weather Service (NWS) has warned that dozens of temperature records could be shattered, with more than 60 million people currently under heat alerts. The heatwave is expected to last several days, potentially impacting everyone, especially those outdoors during the holiday weekend. Many cities across the U.S., including New York City, Philadelphia, Washington, and Chicago, are forecasted to experience their hottest day of the year so far, with temperatures remaining high even at night. As a response, cities have rolled out emergency measures, such as opening cooling centers and providing hydration vans, while event organizers have adjusted schedules to accommodate the extreme conditions. The NWS advises staying hydrated, avoiding strenuous outdoor activities during peak heat hours, and seeking air conditioning or cooling centers where possible to mitigate the risks associated with prolonged exposure to high temperatures.