Devices and methods for heating a fluid to normothermic temperature prior to delivery of the fluid to a patient are disclosed. In one embodiment, a fluid to be warmed prior to delivery to a patient can be passed through a polymeric, flow-through chamber disposed in the fluid delivery line. An electrically resistive heating element for heating the fluid can be molded into the chamber to heat the fluid from room or ambient storage temperatures to a normothermic or body temperature of the patient. A probe of a temperature monitoring element can be used to monitor the temperature of the fluid exiting the chamber. In another embodiment, this information can be relayed back to a controller for controlling the power to the resistance element and hence, the temperature of the fluid. In still another embodiment, an infrared temperature sensor can be used for monitoring the temperature on the fluid exiting the chamber by scanning through a window in the outlet port of the chamber or elsewhere in the fluid line.