During MR examinations, that can last an hour or more, smaller animals can get cold from sedation while larger animals can get hot from RF heating. The Single Pump Fluid Heating System provides a reliable and easy solution for both of these problems. When the patient temperature is less than a user defined set point the blanket temperature is increased conversely when the patient temperature exceeds a user defined set point the blanket temperature is reduced. The heating system consists of a Fluid Heater Module, a Circulator Module, a Reservoir and tubing to connect the Heater Module to a Heating Blanket in the magnet bore. The closed loop system operates with constant flow at low pressure. Fluid volume is approximately 2 liters. The outlet temperature of the Heater Module is controlled around a user selected set point by SAII PC-SAM software running on a Windows based PC. The Circulator Module consists of a circulation pump, a radiator and fan. The pump is low noise with a service life of 30,000 hours.