Fastest way to add calculate damage on different body areas (hit boxes)

What I ask is, what is the fastest way to replicate hit-boxes, like for headshots? I am currently using box colliders for my characters but it really lowers the performance. With about ten characters in my scene the FPS drops from 300+ to <100.

I know it is the colliders because when I disable all the colliders, but keep all the animations and AI running, the FPS shoots up to 300+ again. What would you guys suggest to replace my box colliders or improve the performance?

Colliders is the way to go, I can’t think of any other way to do this.

Performance should not be an issue, i have a scene with a few thousand objects with colliders and it works fine.

Have you added a rigidbody to the characters, or made the colliders static?