Fahrenheit He then re-calibrated his scale using the melting point of ice and normal human body temperature (which were at 30 and 90 degrees); he adjusted the scale so that the melting point of ice would be 32 degrees and body temperature 96 degrees, so that 64 intervals would separate the two, allowing him to mark degree lines on his instruments by simply bisecting the interval six times (since 64 is 2 to the sixth power). Fahrenheit observed that water boils at about 212 degrees using this scale. The use of the freezing and boiling points of water as thermometer fixed
Ice bath known as contrast water therapy or contrast bath therapy, in which cold water and warmer water are alternated. One method of doing this was to have two tubs––one cold (10–15 degrees Celsius) and another hot (37–40 degrees Celsius) ––and to do one minute in the cold tub followed by two minutes in a hot tub, and to repeat this procedure three times. The temperature can vary, but is usually in the range of 50–59 degrees Fahrenheit or between 12 and 15 degrees Celsius. Some athletes wear booties to keep their toes warm or rubberized coverings around their midsection while immersed.