Participants line up for last year’s Cupid’s Undie Run, which raises money for charity. Photo courtesy Cupid’s Undie Run.

Runners, prepare to strip to your skivvies.

You’ve heard about the Cupid’s Chase 5K on Feb. 13. When you’re done with that, you can drop trow at the annual Cupid’s Undie Run on Feb. 20 at the Rattle Inn, 610 Nueces Street.

You don’t have to run in your underpants, but it’s encouraged. Photo courtesy Cupid’s Undie Run.

The event, which features runners in their underpants (well, semi-nudity isn’t required, but it’s encouraged), raises awareness and funds research of neurofibromatosis through the Children’s Tumor Foundation.

Participants trot about a mile through downtown.

Doors open at noon, with an awards ceremony at 1 p.m. and the actual run at 2 p.m. Open bar closes at 3:30 p.m.

We’re lucky we live in Austin. The run takes place in 36 cities around the country, and many of them are colder than Texas. Photo courtesy Cupid’s Undie Run.

Participants can run solo or as part of a team. Registration is $45 now or $55 after Feb. 6. Go here to sign up.

This year’s run takes place Feb. 20 at Rattle Inn. Photo courtesy Cupid’s Undie Run.

Similar runs will take place in 36 cities around the country. (We’ve got it easy in balmy Austin. Watch video of last year’s Cupid’s Undie Run in Cleveland here.) To date, the non-profit event has raised nearly $8 for charity.

This year is special, too. Drew Leathers, the younger brother of Chad Leathers, co-founder of Cupid’s Undie Run and the inspiration for the run, recently died of neurofibromatosis. The genetic disorder causes tumors that grow on nerves throughout the body, leading to blindness, deafness, learning disabilities, cancers and chronic pain.

The event starts at noon Feb. 20. Photo courtesy Cupid’s Undie Run.