There was an experiment in the 19th Century where they tested a Frog's response to be being placed in a pan of water. One time, the water was boiling hot and the Frog was dropped inside the pan.
As you can imagine, the Frog didn't hang around for a bath and immediately jumped out. Another time, the Frog was placed in Cold water and this time, it was slowly heated up. The Frog boiled to Death.