The temperatures are near-record high, but the heat will turn up even more tonight when Joan Jett and the Blackhearts take the stage at Dundalk's Heritage Fair.

As big as Friday night's crowd for Dennis DeYoung was— with people standing on or sitting in every available spot from one side of Heritage Park to the other, officials expect an even bigger crowd for Jett, who grew up in Montgomery County.

The fair is always at the mercy of weather, and late June and early July can be unpredictable, with the possibilities of sudden thunderstorms and triple-digit temperatures.

With three days of extreme heat in store for the event, fait entertainment chairman Bob Fogle said he remains an optimist and hopes people turn out for the celebration regardless of weather.

"I never worry about the weather forecasts; whatever happens, happens," Fogle said Thursday. "We still want the people to come out, no matter what."

Even with muggy, steamy weather conditions, the people did turn out Friday, with both parking and concert spaces hard to find by 8 p.m.

Fair-goers were already talking Friday night about the excitement level over Jett's performance.

As the leader of the Blackhearts, Jett has eight platinum and gold albums, according to her website, and nine Top 40 singles, including "I Love Rock 'n' Roll," "I Hate Myself for Loving You" and "Crimson and Clover," according to her website.

Jett will perform on Stage 1 beginning at 8 p.m.

Another Heritage Fair and Baltimore crowd favorite, Ronnie Dove, will perform at 7:30 p.m. on Stage 2.

Other entertainment throughout the day will include Mark Bray and the American All-Stars (country pop); Gene Vincentt and the Cadillac Cruisers (variety); P.T. Waggs and Django the Monkey; and Dean Crawford & The Dunn's River Band.

Admission to the fair, which includes all concerts, is $5 for adults and children ages 12 and older. Children 11 and younger will be admitted free of charge when accompanied by a paying adult.

Tickets are available at the gate. The fair is held at Heritage Park between Trading Place and Playfield Street in downtown Dundalk.

Pets are not allowed on the fair grounds unless they are needed for medical reasons, according to the event's website. Coolers and outside alcohol and food are prohibited.

The complete entertainment schedule is available at the Heritage Fair website.