Quote Originally Posted by krwright13 View Post
According to "A Comprehensive Russian Grammar" by Terrance Wade, short form adjectives are used to describe temporary states.
Well... This is right... but not exactly right. Grammatically in phrases like "A is B" in literary Russian, B can be either short form adjective or noun, but not full form adjective. When B looks like a full form adjective, in fact it is an adjectival noun.

So "Он болен"="He is sick", "Он - больной"="He is a sick person" or "He is a patient"

Often it has effect described as "short term VS permanent", but not always.