high as a kite

High as a kite is the idiom used for someone who is very high in the air when used literally, and someone who is drunk or drugged when used figuratively. High as a kite is much more commonly used for someone who is intoxicated by drugs or alcohol but it is sometimes used in more of a literal sense. You will usually hear someone is high as a kite when they seem to be acting different than normal, which is common of someone high on drugs.