Thermo-Conductive Blanket Safely Warms Surgical Patients

An innovative patient warming system uses a conductive polymer fabric to deliver safe and effective warming without blowing hot air.

The HotDog patient warming system is based on ThermAssure conductive fabric, which uses low voltage electricity to provide a combination of radiant and conductive uniform heating. The system controller delivers low voltage (48 VDC) electricity to the blankets or mattresses via thin, flexible cables and an electrical bus that runs the length of the blanket to the lightweight, flexible, heater fabric which produces uniform controllable heat that is managed by a microprocessor and a thermistor-type temperature sensor. A second overload thermistor serves as a safety backup.


The semiconductive polymeric heater delivers heat energy evenly, but some surface temperature variations are designed to enhance the blankets’ safety and effectiveness. For example, the temperature of areas not in contact with the patient rises slightly to provide better radiant heat transfer. If a patient contacts this area, it cools instantly, thanks to the low watt density of the heater and low thermal mass of the blanket, which cannot easily store heat. Instead, it immediately cools to the proper temperature for conductive warming.

The low voltage, floating current safety system is sealed in an antimicrobial, nonporous shell that ensures that if a blanket is cut or punctured during use, there no risk of shock or spark to the patient or the clinician. The HotDog patient warming system is a product of DeRoyal (Powell, TN, USA), and provides complete perioperative warming solutions, for supine, lateral, or lithotomy positions or for use in cardiac and burn units. A thin barrier such as a bed sheet, gown, or disposable sheet is recommended between the patient and the Hot Dog blanket to help prevent sweating and possible skin irritation due to residual cleaning agents.

“Surgical patients must be warmed, and HotDog is the safest, most effective and most economical way to provide that warming,” said David Watermeier, senior director of international marketing for DeRoyal. “DeRoyal believes that old technologies such as blowing warm air on patients will soon be replaced with HotDog.”

Surgical patient warming is important for preventing and treating unintended hypothermia, and is the standard of care in the United States. Hypothermia affects nearly all anesthetized patients, and is associated with many complications, including higher rates of surgical site infection (SSI), higher blood loss, higher morbidity, and longer ICU times and hospital stays.

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