What is a Fluid Warmer?

A fluid warmer is a device used to quickly increase the core body temperature by delivering a warmed saline solution intravenously. It can also be used to heat cold intravenous drugs and blood given in transfusions. Fluid warmers have emergency applications, where they can be used in cases of hypothermia brought on by shock from a traumatic injury or from extreme cold. They can also be used during and after surgery, where a patient’s body temperature might drop because of hemorrhage or exposure of opened abdominal or chest cavities.

Hypothermia is a life-threatening condition caused by the body’s core temperature dropping below the normal range of 97.9–98.6°F (36.6–37.0°C). Hypothermia can be caused by prolonged exposure to cold temperatures, by shock following a traumatic injury, and by some types of surgery. Effects of hypothermia include arrhythmia and vascular constriction, so it must be treated quickly, often before other types of emergency treatment can begin. Hypothermia also negatively impacts recovery rates by increasing the chances for infections, heart attacks, and strokes.

A fluid warmer quickly increases body temperature by injecting saline that has been heated to approximately 100.4°F (38°C) directly into the veins. It can be used in conjunction with other types of emergency warming methods, such as warm blankets or respirators that deliver hot moist air, but on its own, a fluid warmer is faster and more effective than any one of these other methods used on its own. Fluid warming is often the first treatment given to victims of trauma and hypothermia.

An intravenous infusion of a cold liquid can also cause the core temperature to suddenly drop. If cold blood is given to a patient, there is a greatly increased risk of cardiac arrest. In these cases, a fluid warmer can also be used to heat blood prior to a transfusion, or to heat intravenously administered refrigerated drugs that must be delivered quickly. An intravenous fluid warmer might also be used during post-operative recovery, since a recurrence of hypothermia is possible and a patient’s body is less able to maintain a normal temperature.

The saline in a fluid warmer can be heated in a warm water bath, or by conduction or convection methods. Some hospital fluid warmers are large machines, intended for use during surgery or post-operation. Other fluid warmers are small, portable, and battery-operated so they can be used by emergency technicians, rescue squads, or medics in the field, in emergency vehicles, or on airplanes.