What Are Cold Reading and Hot Reading Techniques?

Professional mediums would hold public seances as a means of making money. A lot of the tricks that they used were essentially the same things that stage magicians do. Cold reading is when the medium doesn't know anything about the sitters in advance, but is able to deduce information and make high probability guesses from body language. Hot reading is when it's all deduction and guess work from the way the sitters present themselves and what they tell the medium. They would often target people who were planning on attending the seance, and then use assistants who weren't known to the sitters to do the actual research.