In full blast. In the extreme. In America will be heard such a sentence as this: “When she came to the meeting in her yellow hat and feathers, wasn't she in full blast?” A metaphor from the blast furnace in full operation.
To strike by lightning; to make to wither. The “blasted oak.” This is the sense in which the word is used as an exclamation.
If it [the [ghost] assume my noble father's person, I'll cross it, though it blast me.
Shakespeare: Hamlet, i. 1.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894