Fox News 2011 An excessive heat warning is in effect through Friday, with the high temperatures expected near 100 degrees Sunday. Though other events have either moved indoors or been canceled the last few days, U2 is expected to go on.

Berry said sun is better than rain, though in this case not by much.

Joe Abernathy, vice president of stadium operations for Busch Stadium, said: “It is St. Louis, and it will be hot.”

Abernathy says the stadium will take several measures to keep fans as comfortable as possible. There will be three cooling stations at Clark Avenue, with misting fans, a firetruck with a pumper spraying water and free drinking water. On the field, fans will find two cooling stations and free water.

There will also be extra paramedics and rooms inside the stadium with air conditioning.

Concertgoers are advised to watch their alcohol intake, dress appropriately and to wear hats and sunscreen.

Fans who’ll enjoy the show on the field’s general admission surface shouldn’t wear flip-flops. “A couple of steps on this hot deck at 5 o’clock and you won’t last long,” Abernathy said.

Berry says U2 will feel the same weather as the fans.

Concertgoers can bring water and soda into Busch Stadium, but those beverages must be in open cups or clear plastic bottles.

They can also bring backpacks, purses, diaper bags, fanny packs and soft-sided coolers that don’t exceed 16 inches by 16 inches by 8 inches. Small personal cameras are allowed. All bags must be able to fit under a seat.