Karlee, on the week of her third birthday, was in Boston undergoing treatment for leukemia. In order to distract her, if only for a brief time, a party was staged for her.

“She was really shy at first, because she walked in and there were 40 of us in one room,” said Jen Caruso, a fifth-year Northeastern student. “But she really warmed up. We had pizza and cake and just celebrated her.”

Karlee’s birthday party was held in a university classroom by the students who

run Northeastern’s chapter of Love Your Melon, a national charity that aims to provide a hat to every child undergoing treatment for cancer. Karlee enjoyed a Minnie Mouse cake in honor of her favorite character.

Love Your Melon has grown to reach more than 760 schools across every state since its creation six years ago by two students in an entrepreneurship class in Minnesota. The hats are offered to kids with cancer, whether they are undergoing chemotherapy or not. Last month Caruso and her Northeastern colleagues joined students from other colleges to visit children at several Boston-area hospitals.

“We spend an hour or so with the children on the oncology floor,” said Caruso, the president of Northeastern’s Love Your Melon Campus Crew. “We let them pick out a beanie and just do arts and crafts with them, or whatever they like. It all depends on what kind of day the child is having, because sometimes they have treatment that day.”

Sometimes the kids aren’t having the best day. They’re upset, and it’s heartbreaking to see these little children battling this awful, awful disease. You go to clinics on a Monday morning when they should be at school, but instead they’re having treatment. To be able to help put a smile on their face, even if it’s just for an hour, that is one of the most rewarding things.

Jen Caruso, Northeastern student

The visits are distressing and inspiring.

“Sometimes the kids aren’t having the best day,” Caruso said. “They’re upset, and it’s heartbreaking to see these little children battling this awful, awful disease. You go to clinics on a Monday morning when they should be at school, but instead they’re having treatment. To be able to help put a smile on their face, even if it’s just for an hour, that is one of the most rewarding things.”

Caruso’s 18-year-old cousin, Matthew Cirelli, died in 2013 of Ewing’s Sarcoma, a rare cancer that grows in and around the bones. Her family is developing a nonprofit in Cirelli’s memory.

“He is why I became so involved,” said Caruso, who has applied to physician assistant’s school and is hoping to work in pediatric hematology-oncology.

Many of the Love Your Melon volunteers at Northeastern have a personal relationship with the disease.

“It really affects a lot of people,’’ said first-year student Amanda Marom, whose cousin had cancer and whose mother is fighting the disease. “Even if you’re not directly affected, you definitely know someone who knows someone who has it.”

Northeastern’s campus crew will be preparing dinner on Nov. 30 for Boston’s Ronald McDonald House, which provides support of all kinds for sick children and their families. The volunteers will also be assembling holiday packages to donate to the oncology unit at Boston Children’s Hospital next month.

Since 2012, the Love Your Melon Fund has generated almost $5 million in donations while handing out close to 150,000 beanies. Fifty percent of all apparel sales at loveyourmelon.com are earmarked for the nonprofit fund.

Northeastern’s chapter of Love Your Melon is part of the university’s “Give, Inspire, Transform” campaign to raise money for student groups dedicated to improving the lives of people in local communities.

“The beanies are addressing a need that maybe they wouldn’t have had before their treatment,” said Caruso, whose crew has provided as many as 500 hats to children during her four years with the charity. “Every time we have an event with a family, we have monthly check-ins with them, just to make sure that they’re still being recognized and remembered.”

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