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TCCC committee’s guideline for hypothermia management

Co-TCCC guideline update hypothermia management showing a sleeping bag, HPMK, and other options
Mike Shertz MD/18D

In 2021, the TCCC Committee changed to hypothermia management for combat casualties.

Researched and written by Mike Shertz, MD/18D, not AI

🕖 Reading Time, 3 minutes

The Co-TCCC noted there had been no review of hypothermia management in the guidelines in the previous 14 years.1
So what changed?

Warming the casualty becomes an immediate priority

The hypothermia management guidelines remind rescuers to make keeping the casualty warm a more immediate priority. Where possible, it is essential to minimize exposure to the cold ground, wind, and water/rain.

Adding an external source of heat to the casualty, like an active warming blanket, ready heat warmers, etc. is desirable. As a reminder, the ready heat blanket in the current generation Hypothermia Prevention and Management kit can achieve temperatures of 125F for ten hours. Therefore, it should never be placed directly on the skin, because it could burn the casualty. Similarly, it should never be placed under the casualty as their body weight pressing on the heating blanket can also cause burns, even with a layer of clothing between casualty and heat source.

The HPMK alone may not be enough

One study showed the HPMK might not be the optimal system to keep casualties warm. Although it provides a heat source and vapor barrier/external wrap for the casualty, there is no insulating material/layer. Optimally, the guidelines recommend placing the casualty in a mummy-style sleeping bag, after the heating blanket is placed on their chest, and then enclosing the entire package in an exterior vapor barrier, like the heat reflective shield of the HPMK.

Though it seems reasonable to place the casualty in a sleeping bag inside the HPMK, if both are available, the study used to show the superiority of that technique was for casualties expected to have prolonged cold environment exposure. Specifically, five volunteers were placed in various hypothermia management systems and then moved to a -22C (-7.6F) cold room for an hour. As guideline indicates, if prolonged cold environment exposure is anticipated for the casualty, the non-insulated HPMK is not enough.2

Operationally, if the area is cold enough to carry sleeping bags and pads, they should be integrated into the casualty management plan.

IV fluids and blood need to arrive warm too

Finally, Co-TCCC guidelines direct IV fluid or blood administered prehospital be should be through a battery-powered fluid warming system capable of delivering 150 ml/minute flow with an output temperature of 100F (38C).1 No specific device is recommended. Currently, there appear to be five such systems commercially available. Only four have been studied in the medical literature. Based on the study by Lehavi comparing four of the systems, only the Warrior and EnFlow seemed to come close to meeting these requirements.3 Unfortunately, there have been issues with the EnFlow using an aluminum warming plate, which has allowed aluminum to leach into electrolyte solutions, such as IV fluid. They have since been recalled.1

The NAR device called the Quantum has not been tested in peer-reviewed medical literature yet but was created with SOCOM funding and likely will meet these specs as well.

For a quick video on the subject: There is a Long-held SF tradition of always being prepared to provide a block of instruction during down time.

Cold blood does not clot: keeping casualties warm must be part of your casualty management strategy.

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References

1 Bennett BL, Giesbrect G, Zafren K, Christensen R, Littlejohn LF, Drew B, Cap AP, Miles EA, Butler FK Jr, Holcomb JB, Shackelford SA. Management of Hypothermia in Tactical Combat Casualty Care: TCCC Guideline Proposed Change 20-01 (June 2020). J Spec Oper Med. 2020 Fall;20(3):21-35.

2 Dutta R, Kulkarni K, Steinman AM, Gardiner PF, McDonald GK, Giesbrecht GG. Human Responses to 5 Heated Hypothermia Wrap Systems in a Cold Environment. Wilderness Environ Med. 2019 Jun;30(2):163-176.

3 Lehavi A, Yitzhak A, Jarassy R, Heizler R, Katz YS, Raz A. Comparison of the performance of battery-operated fluid warmers. Emerg Med J. 2018 Sep;35(9):564-570.

Key Takeaways

  • Keeping a casualty warm is now framed as an immediate priority, not a secondary step once bleeding is controlled.
  • The HPMK alone has no insulating layer — add a sleeping bag underneath it when prolonged cold exposure is expected.
  • Never place a warming blanket directly against skin or under a casualty’s body weight; both risk burns.
  • IV fluid and blood given prehospital should be warmed to roughly 100F (38C) at 150 ml/min — the Warrior and EnFlow have come closest to that spec, though the EnFlow has since been recalled over an aluminum-leaching issue.
  • If the environment is cold enough to justify carrying sleeping bags and pads, build that into the casualty management plan up front.
Picture of Mike Shertz MD/18D

Mike Shertz MD/18D

Dr. Mike Shertz is the Owner and Lead Instructor at Crisis Medicine. Dr. Shertz is a dual-boarded Emergency Medicine and EMS physician, having spent over 30 years gaining the experience and insight to create and provide his comprehensive, science-informed, training to better prepare everyday citizens, law enforcement, EMS, and the military to manage casualties and wounded in high-risk environments. Drawing on his prior experience as an Army Special Forces medic (18D), two decades as an armed, embedded tactical medic on a regional SWAT team, and as a Fire Service and EMS medical director. Using a combination of current and historical events, Dr. Shertz’s lectures include relevant, illustrative photos, as well as hands-on demonstrations to demystify the how, why, when to use each emergency medical procedure you need to become a Force Multiplier for Good.