When hairdrying your hair, one hand (the hand you ruffle your hair with) gets warm due to the warmth of the air blowing out of the hairdryer, and one hand (the hand holding the hairdryer) is cold.
Brought to public attention by Bob Woodward and Carl Bernstein in the book on the fall of Richard Nixon, All The President’s Men, ratfucker was Nixon’s term for a political operative who sows chaos among opponents; an agent provocateur. It is thought to have originated among campus political rivalries at USC, and seems to have some usage in the US military.
Along with Nixon’s other ratfuckers, Roger Stone caused fights at otherwise peaceful Democratic Party protests to generate a false narrative that the Democrats were violent and dangerous.