Undeterred by freezing temperatures and a stiff breeze, several hundred hardy individuals jogged along city streets wearing nothing but their underwear to raise money for charity in the tenth annual Cupid’s Undie Run in Washington, D.C., on Saturday, Feb. 10.

The event, which started in the District in 2010 and takes place around Valentine’s Day, has expanded to 38 cities across the U.S. and another 12 in Australia. Proceeds support the Children’s Tumor Foundation’s fight against neurofibromatosis, also known as NF, a rough cancer that affects the nervous systems of small children. The genetic disease which can cause blindness, deafness, learning disabilities and severe chronic pain affects 1 in every 3,000 children born.

Before and after the race, runners were able to loosen up at Penn Social located in Washington D.C.’s Penn Quarter with on-air personality Elizabethany of HOT 99.5 serving as MC.

An added event this year is the “Bathrobe Brunch” where participants show up to “a luxurious brunch in their luxurious bathrobes”.

Brendan Hanrahan, Bobby Gill and Chad Leathers came up with the idea for the run, which was first held on Capitol Hill. Leathers’s brother Drew was affected by NF, and the founders wanted to do something to raise money for research on the disorder. They expected about 100 racers that first year, but more than 600 showed up, raising $10,000. In 2012, Cupid’s Charity became a recognized 501(c)(3) nonprofit and since its inception has raised $16.9 million. Hanrahan was joined this year by race director Ashley Casper and co-race director David Dosberg.

“Freezing” said Anna Johnson after completing her scamper through the streets of her home town wearing very very very little. “It felt like my hands were going to fall off. It might be one the fastest miles I’ve ever run, just out of survival. But I guess its worth it. It’s all for kids.”

Those interested in learning more about and donating to the Children’s Tumor Foundation should click here.

View Jeff Malet’s photo from Cupid’s Undie Run in D.C. by clicking on the photo icons below.