A healthy dose of Panic!

Panic! at the Disco

With: Bloc Party, Jack’s Mannequin

When: 7 p.m. Saturday (doors 5:30)

Where: Patriot Center, Fairfax

Tickets: $35 Details: (804) 262-8100 or www.ticketmaster.com or www.patriotcenter.com

Spencer Smith knows about heat. After all, he and his Panic! At the Disco band-mates hail from Las Vegas, where an average day in July is 110 degrees.

But on Tuesday he’s calling from Fort Lauderdale, Fla., preparing for the launch of the band’s arena tour that night.

“I’m standing outside in Florida in the middle of November and sweating,” he says, by way of explaining why he, guitarist Ryan Ross and singer/guitarist Brendon Urie still live in Vegas (bassist Jon Walker comes from Chicago; original bassist Brent Wilson parted with the band in May). “We always talked about how we wanted to move out of Vegas, until we went on tour and saw other places and were like, you know, Vegas isn’t so bad!”

Panic! At the Disco, which takes its name from the Smiths song, “Panic,” is one of those Cinderella stories. The band is young — drummer Smith and Urie are the babies at 19, Walker the old man at 21 — and scored its first break by being signed to the vanity label of Fall Out Boy’s Pete Wentz . . . before they ever played a live gig.

Panic’s debut, “A Fever You Can’t Sweat Out,” arrived in September 2005 and is filled with surprisingly literate power pop. While making the hearts of the MySpace brigade pound with every wave of their ruffled-shirted arms, the quartet managed to land a format-crossing hit.

“I Write Sins, Not Tragedies” is a rock song about a bizarre wedding. It’s dusted with strings and contains the phrase “poise and rationality” in the chorus.

Fergie, it’s not.

There have been newer hits, too, with equally amusing titles that suggest these young men have spent time with dictionaries and thesauruses (“The Only Difference Between Martyrdom and Suicide Is Press Coverage,” “Lying Is the Most Fun a Girl Can Have Without Taking Her Clothes Off”).

The Panic boys have also attended the staple entertainment of Vegas — the various Cirque du Soleil shows — and used its peculiarities as inspiration for their own live show.

Smith happily discusses the new tour and the band’s meteoric rise:

What can you tell us about the new show?

We have six other performers with us. They’re amazing. We just met them in Miami when we got here a few days ago. We’ve also got all of these stage props. I had an idea for my drum riser, to make it look like a carousel, so it’s 8 feet off the ground. I was a little nervous about it, but when I saw it a few days ago, it was fine. And I have the best seat in the house!

[The show] is definitely not like the Barnum & Bailey Circus, it’s more from an older time. We looked at pictures, black and white photos from circuses from the ’20s and noticed that the clowns weren’t these big red cheeks with white face painting. It’s more dreary. We thought that [motif] was cool and took it into consideration.

Did you purposely create this kind of atmosphere as a response to the bands who just show up and stare at the stage floor for two hours?

When we were growing up, we’d go see the bands we liked and then we’d see the Cirque shows and then it became, wow, there’s a lot more that can be going on in this concert. A lot of bands feel comfortable walking out in jeans and T-shirts and that works for some bands, but we wanted to do something more.

Is it true that Jimmy Page came to see a show this year?

Yeah, in the spring in L.A. He’s a good friend of one of the people at our record label and I think his daughter likes our band. I called my dad right after [meeting him]. He was one of the first people we met who was famous but also had relevance to what we’re doing.

You’re playing some big venues for a new band. How are you handling this rapid success?

It’s been very quick for us, but I guess it’s one of those things where we’re here and doing it every day. For us it’s fast, but this is the first time any of us has been in a band, so we have nothing to base what’s normal. So it’s fast based on other bands and how fast their success may or may not have come. But it’s been somewhat of a steady progression. We’re all very level-headed. I don’t think there will be any problems.