Disney Celebrates America live updates: ABC marks America's 250th anniversary

Due to the extreme heat, gates will open at 7 p.m. Friday for the 8 p.m. Capitol Fourth Concert at the U.S. Capitol in Washington, D.C., police said.

The heat index -- what temperature it feels like with humidity -- was forecast to hit a scorching 113 degrees in D.C. on Friday.

"To ensure a safe concert, all guests are strongly encouraged to bring an ample supply of water," Capitol police said. "Non-glass water bottles and coolers are allowed."

In Philadelphia, the Salute to Independence Semiquincentennial Parade set for Friday has been canceled due to the dangerous heat wave, according to Philadelphia ABC station WPVI.

The coverage kicks off at 10 p.m. ET on Friday, July 3 with an unforgettable landmark, artistic event transforming the public's experience of the Statue of Liberty with the Consulate General of France and Muir taking viewers along for a rare look inside of Lady Liberty.

As the clock strikes midnight on Saturday, July 4, ABC News will bring audiences to the first parade in the nation in Gatlinburg, Tennessee.

"Good Morning America" will have a special three-hour show which will include co-anchors Robin Roberts, George Stephanopoulos and Michael Strahan sharing their own American journeys.

After "GMA," ABC News anchors and correspondents will welcome viewers to the 7 Wonders of America and cities across the country, showcasing the majestic geography, cultural heritage and pivotal moments that define 250 years of American history, along with celebrations, performances and interviews with leading newsmakers.

In the afternoon, ESPN will air the finals of The Nathan's Famous Hot Dog Eating Contest, with champions Joey Chestnut and Miki Sudo set to return to Coney Island to seek a new world record.

In Washington, D.C., the Great American State Fair abruptly closed mid-day Friday due to the dangerous temperatures, organizers said.

The heat index -- what temperature it feels like with humidity -- is forecast to reach a scorching 113 degrees in D.C. on Friday.

Organizers said the fair will reopen at 5 p.m.