What does "when worn" mean?

[FireHorse]

Originally Posted by Skarg

I think someone who wants magic that will let them keep a dozen "lit but not burning at the moment" grenades ready to explode when the spell ends, should research a new Suppress Combustion spell, and if the GM decides it should exist, it should not be as cheap in IQ or ST cost as Darkness.

I think that spell should be called Delayed Combustion, and it should be bound to the grenade with an object which, when removed, ends the spell and makes the grenade active. The object could be something simple, like, say… a Pin. And it could be built into the grenade at the time of manufacture…