Millions of Americans could experience hottest July 4th ever

This July Fourth could be the hottest on record for millions of Americans as a massive heat wave traps more than half of the United States under a heat dome through the holiday weekend . Dangerously high temperatures, coupled with humidity, could result in heat indices of 100 to 115 degrees from the Midwest to the East Coast, forecasters said. Between daily high temperatures and warm overnight lows — which won't be low enough to offer much relief — more than 300 records are expected to be set by Saturday. "These are extremely dangerous conditions," New York City Mayor Zohran Mamdani warned the city of over 8 million residents. A forecast map shows the heat index approaching or topping 100 degrees in much of the eastern U.S. CBS News For the first time, New York City is deploying vans staffed with nurses and paramedics who will hand out water, electrolytes and sunscreen, CBS News New York reported . They will also perform wellness checks, transport people to cooling centers and make in-home visits to vulnerable residents. The city is also opening cooling centers throughout the five boroughs. …