An alcohol rub can rapidly decrease body (skin) temperature.
(a) This is because of (1) the cooler temperature of the alcohol, (2) the evaporation of alcohol, (3) the high specific heat of the human body.
(b) To decrease the body temperature of a 65-kg person by 1.0oC, what mass of alcohol must be evaporated from the person’s skin? Ignore the heat involved in raising the temperature of alcohol to its boiling point (why?) and approximate the human body as water.