Channellers, like all other mages, know what kind of wear and tear their
hazardous lifestyles can exact on garments or gear. Blasts of fire, spills of
acid, and sizzling lightning are day-to-day occurances with them. After
learning to channel the energy from inside an object to them, they learn how
to pull the energy from outside the object, thereby pulling some of the
harmful energies -- kinetic, thermal, whatever -- to them. While this can (and
indeed often does) hurt quite a lot, flesh heals and steel doesn't.
Channellers often cast this spell on their prized golems, but it will work on
just about anything. You can cast this spell at yourself to check how many
shields are still active.