Help turning off objects when rendering to RenderTexture (like health bars)

Suppose my character runs around with a health bar on top of his head. When looking at a mirror or video display of himself, I would like the health bar NOT to appear in his reflection. How do I go about doing that?

I am using a Camera and a Render Texture to create this effect.

Can I detect what camera is being rendered to and disable my health bar? But when would I do that…in the OnUpdate of my HealthBar object???

Thanks.

Use layers.

Set any in-world UI elements to a UI layer, disable that layer on the reflection camera.