Here in Louisiana, flip-flops are almost a year-round part of our wardrobe.

Now there’s National Flip-Flop Day, a time to celebrate our favorite footwear. In honor of the occasion, Tropical Smoothie Café in Slidell will offer free smoothies to the first 500 customers wearing flip-flops.

From 8 a.m. to 8 p.m., today those first sandal-sporting folks can get a free Jetty Punch smoothie, a strawberry-banana concoction sure to cool things off as the mercury climbs. The event is more than just a promotion to celebrate the start of summer. The franchise is also raising money to send a Mandeville girl to Camp Sunshine, a retreat located on Sebago Lake in Maine that provides respite and support to families of children suffering with a terminal illness. The program is free of charge to all families and includes 24-hour onsite medical and psychosocial support.

Founded in 1984, the camp has hosted over 30,000 people, and relies on donations and fundraising events such as this to provide the programs at no cost to participants.

The Slidell restaurant, which opened last September, will send Mandeville resident Katie Miller, 5, and her family to the camp this year. According to Katie’s mom, Diana Velez, the youngster was diagnosed with a Wilm’s tumor in 2005 at 12 months of age.

“She wasn’t crawling, so at her 12-month checkup our pediatrician referred us for an MRI,” said Velez. “She had to have her right kidney removed, and then go through 18 weeks of chemo that finished right before Hurricane Katrina.”

Also known as nephroblastoma, the tumor is the most common malignancy of the kidneys in young children. It occurs when the embryonic cells that normally form the kidneys do not mature, and instead turn into cancer.

Now in remission, Katie will be considered cured after five years, but is also considered more likely to get a secondary cancer, such as leukemia, in another part of her body in later years. She must go twice a year for follow-ups with an oncologist to make sure the chemotherapy treatments have not damaged her heart or other organs.

Velez found out about Camp Sunshine earlier this year while researching the American Cancer Society for family camps.

“Katie is very strong and confident, but she’s still shy,” said Velez. “Most camps you just send a kid away by themselves, and even my older daughter, Emmy, would not go for that.”

The girls’ mother found there are a small number of camps where the whole family can attend. She contacted Camp Sunshine and they put her in touch with Tropical Smoothie.

Katie and Emmy, 6, will travel to Camp Sunshine later this summer with Velez and her husband, and all are “very excited.”

According to owner Rene Arcemont, customers may make donations by purchasing a paper flip-flop. In addition, 10 percent of all proceeds will go directly to Camp Sunshine. Nationally, the chain has raised over $125,000 for the program, and several local companies have also partnered with the Slidell store as sponsors: Iberia Bank, Expo Signs and Southern Surgical Hospital.

The campaign will continue through the end of June.

Tropical Smoothie Café is located at 2040 Gause Blvd. East, and a second location is planned to open in Mandeville. For more information, call 643-3328, or go to www.tropicalsmoothiecafe.com.