Ashlyn Blocker's parents and kindergarten teachers all describe her the same way: fearless. She is fearless because she can feel no pain.

In the school cafeteria, teachers put ice in 5-year-old Ashlyn's chili, because even though her lunch is scalding hot, she'll gulp it down anyway.

Ashlyn has chewed through her tongue while eating, and once tore the flesh off her finger after putting the finger into her mouth.

Ashlyn is among a tiny number of people in the world known to have congenital insensitivity to pain with anhidrosis, or CIPA—a rare genetic disorder that makes her unable to feel pain.

Family photos reveal a series of these self-inflicted injuries. One picture shows Ashlyn in her Christmas dress, hair neatly coifed, with a swollen lip, missing teeth, puffy eye, and athletic tape wrapped around her hands to protect them. She smiles like a little boxer who won a prize bout.

Tara Blocker, Ashlyn's mother, says, "Pain's there for a reason. It lets your body know something's wrong and it needs to be fixed. I'd give anything for her to feel pain."