Using game objects to modify a Shader

Is there a way I can check a pixels distance to a game object, in a shader. Say I have a metal shader, and I want it to glow red hot if it gets near a game object, but only at the points nearest, NOT the whole thing.

Or a more simple way to look at it, is there a way I could compare a texels location in world space, to the location of a game object, also in world space?

I am not looking for a simple Blinn shader that uses a public range value to change the color and brightness.