Update: By the end of the dance-a-thon, THON had raised $11,696,942.38, up from $10.6 million last year. This brings THON’s overall fundraising total since 1973 to $179.7 million, securing THON’s spot as the largest student-run philanthropy in the world.

When Julia Duemler was a little girl with long, curly blond hair, her father would carry her on his shoulders and sing “You Are My Sunshine.”

“Like, I was the sunshine on his shoulders,” she said.

His death 10 years ago from colon cancer was devastating to Julia, then just 11 years old. This weekend, Julia, still sporting those long blond curls as a student at Pennsylvania State University, will think a lot about her father. She’ll dance for him. She’ll dance against cancer, and she’ll dance for all the children who have it — and for those who have beat it.

Julia, a senior from Montgomery County, is one of more than 700 student dancers participating in Penn State’s 46-hour dance marathon, known as THON. It’s billed as the world’s largest student-run philanthropy, netting $168 million for pediatric cancer research and family support since it started nearly a half century ago.

About 16,500 students — about 20% of the student body not counting its World Campus — volunteer, filling a variety of roles including public relations, security, support for dancers, hospitality, and fund-raising. Many student organizations, including fraternities and sororities, athletic teams, and clubs, participate, as do the other Penn State campuses. Each organization is paired with families affected by cancer, and students spend time with the families during the year and again on the dance floor. Donors can make general pledges or target money toward specific dancers or groups at https://donate.thon.org.

While many other large universities hold dance marathons as fund-raisers, Penn State’s is a pioneer that others have sought to emulate, said Linda Durant, vice president of development at the Council for Advancement and Support of Education in Washington.

“Students are seeing firsthand the impact of raising money and what that can do, and how that can be fun at the same time,” she said.

Thousands will pack the Bryce Jordan Center for kick off at 6 p.m. Feb. 21 — coincidentally, the anniversary of Julia’s dad’s death — then watch dancers until its conclusion at 4 p.m. Feb. 23. Once it starts, the rules say, dancers may not sit or sleep. They can, however, take short breaks to soak their feet in ice, use the bathroom, or get a piggyback ride.

Julia has prepared: She weaned herself off caffeine (to avoid energy crashes) and has been working out five times a week. Her mother and sister will be there to support her. So will her father, in a way.

“I’m dancing for my sunshine," Julia said, "which is my Dad.”

A search for four diamonds

The first THON, though it wasn’t called that initially, was held in 1973, with just 78 dancers. It raised a little over $2,000. By 1977, the Four Diamonds charity, based at Penn State Children’s Hospital in Hershey, became THON’s sole beneficiary after students heard its founder, Charles Millard, on a campus radio show. Millard had lost his son, Christopher, to cancer at age 14, and he and his wife started the charity to help other families.

Four Diamonds got its name from a story that Christopher wrote about a knight’s search for four diamonds, which symbolized courage, wisdom, honesty, and strength, a tale Christopher’s family saw as symbolic of his fight against cancer. The story was turned into a Disney TV movie in 1995.

Millard, now 91 and living in Washington state, has returned annually for THON, and over the decades, its fund-raising power has grown. In 1983, it hit six figures, then passed $1 million in 1992. Every year, students were fixtures at intersections and at storefronts from Boston to Washington, holding cans and soliciting donations, “canning” as it was called.

THON’s annual record, $13.3 million, came in 2014. Then THON phased out canning following the death of a student in a car accident as she returned with others from a canning weekend in Chester County. Donations fell.

» READ MORE: Who’s in charge of the world’s largest student run philanthropy? A Penn State student from Huntingdon Valley

Still, THON, which turned to more online fund-raising and brought in $10.6 million last year, is responsible for more than half the money Four Diamonds receives annually, supporting 400 to 500 families, said Suzanne Graney, executive director. THON also has inspired more than 260 “mini-THONs” at high schools in five states, which raised $7.2 million for Four Diamonds last year. Julia helped start one at her high school, Upper Perkiomen.

The money fills gaps that insurance does not, such as pharmacy costs and co-pays, and provides art and music therapy, counseling and logistical support to children and their families, Graney said.

THON, she said, “made a huge, huge difference in what we’ve been able to accomplish, in terms of what we can offer in direct support to the families and what we can do to look for a cure.”

Comfort in a dark time

Julia knows what it’s like to feel that kind of support. After her father’s diagnosis, a local charity, now called For Pete’s Sake, sent the Duemlers to Disney World for a week. Julia remembers the comfort that trip brought at such a dark time.

“Just being able to have fun for a week and not think about cancer or chemotherapy, I really relate that to THON,” she said.

Julia was 8 when her father got sick. She remembers it as a confusing time when her grandmother babysat a lot.

“I just felt very alone and didn’t know what was going on,” Julia, a mathematics major, told me. “I wanted to help my Dad feel better, but I didn’t know what to do.”

(I grew up a few houses away from Julia’s mom, Lisa Dent Duemler, and have known her since we were in elementary school. I also knew her husband, Dave, and attended their wedding and spent time with the family while they were dealing with Dave’s illness.)

Dave Duemler founded and ran Demco Automation, which designs and manufactures automation systems. Sporting an athletic build and broad smile, he was a top-ranked member of the U.S. luge team and competed in the World Cup series.

» READ MORE: This local couple refuses to let patients fight cancer battles alone

A graduate of the former Spring Garden College, Duemler became an avid Penn State fan, thanks to his wife, a 1984 graduate. The family attended football games and vacationed with other alumni.

Then came cancer. But Duemler was determined to make the best of his time. “If it’s not fun, I’m not doing it," he said. That led to impromptu family weekend trips, from Hershey Park to the beach.

Duemler died at 46. But before his death, he volunteered with For Pete’s Sake and served on its board of directors. That stuck with Julia. Even when he was at his sickest, her father thought of others.

A sense of pride

Like football and tailgating, THON has united generations of Penn State families. Julia’s mom danced for her sorority, Delta Gamma, when she was a student. That’s the same sorority that Julia will dance for.

“I remember it being tough,” Lisa Dent Duemler said. “You’re kind of zombie-ish.”

Julia’s uncle, former U.S. Rep. Charlie Dent, also danced as a student for his fraternity, Phi Kappa Psi, but didn’t quite finish. He had a mild cold, he recalled.

“I think I danced for about 30-some hours, and then there was a stretch break, and that’s the last thing I remember,” said Dent, who works for the law firm DLA Piper and is a CNN contributor. “Apparently, I had passed out."

He returned a few years ago when his daughter helped out.

“You get an overwhelming sense of pride about how these students channel all this energy for a really important cause,” he said.

Julia’s older sister, Anna, got involved in THON her freshman year and danced in 2018. She danced for her dad, too.

“It’s such a fun, happy place," Anna said of THON, "and as you know that’s what my dad was all about, especially at the end.”

Anna, who got her degree in biology and works in the ovarian cancer research lab at the National Institutes of Health, still keeps more than 50 letters that friends and family wrote to her before she danced. She pulls them out and reads them if she feels sad.

“I will be cheering you on the entire weekend," her best friend wrote, "but more importantly, your dad will be cheering you on and dancing with you.”

» READ MORE: Penn State's THON raises more than $13 million

Now, it’s Julia’s turn. She’s determined to finish.

“Everything I do now has always been about trying to make my dad proud,” she said. “That’s how I live my life, including THON.”

Reporter Susan Snyder will report live updates on THON throughout the weekend on Inquirer.com and publish a follow-up story about THON’s current executive director, Huntingdon Valley’s Regina Duesler, on Monday, Feb. 24.