US celebrates July 4 amid heat warnings

A fan watches a July 4 fireworks display after a baseball game between the Kansas City Royals and the Tampa Bay Rays (Charlie Riedel/AP)

Millions of people in the US celebrated under heat warnings as they flocked to beaches and travelled to toast their nation’s birth with July 4 parades, cookouts and fireworks.

Travel records were projected to fall with people jamming airports and crowding highways to reach Thursday’s Independence Day celebrations, which will stretch into a long weekend for many.