As Independence Day festivities loom for millions across the central and eastern United States, extreme heat warnings threaten to overshadow the nation’s birthday celebrations. Sweltering conditions raise concerns for public safety and holiday travel alike.

Millions of residents across the Southwest are on high alert as a massive heat wave threatens triple-digit temperatures through the weekend. Officials are opening cooling centers and urging caution, while tragic heat-related deaths underscore the urgency of the warnings.