A body part temperature regulating apparatus is provided that regulates a temperature of a part of a human body or an animal body. The body part temperature regulating apparatus including a controller that receives a first input from a first temperature sensor detecting a temperature of a heat transfer fluid at a first location, a second input from a second temperature sensor detecting a temperature of the heat transfer fluid at a second location, and a third input from a flow sensor arranged to detect the flow rate of the heat transfer fluid. The controller determines the amount of heat transferred to the heat transfer fluid using the first, second and third inputs during a first predetermined period of time and outputs a control signal to regulate the amount of heat transferred to the heat transfer fluid based on the determined amount of heat transferred.
