Incremental steps towards disaster. Derived from the old saying that if you place frogs in cold water and bring it to a boil, they won’t know they are about to die, as opposed to tossing them into boiling water. Phrase is used anytime one is referencing a situation that is slowly getting worse.

“First the boss took away our vacation pay, than he shortened our work week and gave no pay raises, we are boiling frogs and may soon be without a job.”