Death of the Golden Hour

Adapting the Army Health System for Denied Environments

By Sgt. Maj. Eric Pelkey, Master Sgt. Leann Miller, and Master Sgt. Peter Stednick

Article published on: July 1, 2025, in the July 2025 Issue of The Pulse of Army Medicine.

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Banner source: U.S. Air Force by Senior Airman Vernon R. Walter III

ABSTRACT:

As large-scale combat operations (LSCO) and multi-domain operations (MDO) reshape the future operational environment (FOE), traditional casualty care models face increasing challenges. The concept of the “Golden Hour” is no longer a universally achievable standard due to contested logistics, denied communications, and delayed medical evacuation. Therefore, the Army Health System (AHS) must shift from rigid evacuation timelines to a capabilities-based model of care. It highlights the disparity between the terms “Golden Hour” and “Golden Day,” addressing how doctrinal misalignment can impact operational planning. Additionally, it examines the physiological realities of trauma care, ethical concerns surrounding prolonged casualty management, and the risks associated with over-reliance on emerging technologies. To adapt, the paper advocates for flexible evacuation doctrine, enhanced Role 1 capabilities, cross-functional training in Prolonged Casualty Care (PCC), and realistic medical planning. Bridging medical capability and operational feasibility is crucial to sustaining force survivability in contested environments.

The evolving nature of warfare compels leaders to reassess long-established operational practices to support decentralized, high-intensity, and multi-domain operational environments (OE). The challenges of contested logistics, denied communications, and delayed evacuations define FOEs and undermine the sustainability of traditional medical care models. (U.S. Army Futures Command, 2023). However, maintaining continuous force flow and minimizing the operational impact of casualties remains essential for mission success. The AHS has historically played a pivotal role in preserving operational reach, especially during counter insurgency (COIN) operations, where medical evacuation (MEDEVAC) capabilities were relatively predictable and accessible (Joint Chiefs of Staff, 2020). Competent near-peer adversaries, contested airspace, and denied battlespace connectivity increasingly define emerging conflict zones, severely constraining situational awareness and degrading command and control. The widespread proliferation of sensors and precision-targeting systems compounds these challenges by diminishing the ability to conceal friendly movements, increasing exposure to persistent surveillance and attacks, and ultimately intensifying the complexity and duration of engagements. (U.S. Army Futures Command, 2022). Thus, Army Medicine requires a paradigm shift in how they contribute to the fight. To adapt, Army leaders have identified three medical imperatives: clearing the battlefield, maximizing return to duty, and overcoming contested logistics (Army Medical Department, 2022). These imperatives anchor survivability strategies and necessitate synchronized support across the DOTMLPF-P modernization framework.

The “Golden Hour” and the Rise of the “Golden Day” Lexicon Disparity and Conceptual Confusion

The foundational principle of the “Golden Hour,” first introduced in the 1980s, stresses the importance of delivering surgical intervention within 60 minutes of traumatic injury to optimize survival (Eastridge et al., 2010). This physiological reality has underpinned decades of battlefield trauma doctrine. However, as OEs become more complex, the feasibility of meeting this standard has diminished. In response, senior leaders coined the term “Golden Day” to reflect operational constraints and the necessity for extended forward care (South, 2021). Though meant as a practical adaptation, this shift in lexicon unintentionally stirred confusion, especially among non-medical personnel who interpret both terms in logistical rather than physiological manner (Johannigman, 2018; Sallette, 2017). Unfortunately, this misunderstanding can lead to flawed planning, under-resourced care, and inflated expectations about survivability windows.

Misaligned Expectations

In 2009, then-Secretary of Defense Robert Gates institutionalized the “Golden Hour” as a one-hour evacuation benchmark, emphasizing that survival is highly time-dependent (Gates, 2009). The Army medical community quickly adopted this standard into doctrine, integrating it into key planning documents such as Field Manual (FM) 4-02, Army Health System, and Army Techniques Publication (ATP) 4-02.2, Medical Evacuation (Department of the Army [DA], 2019; DA, 2020). For example, Figure 1 illustrates the scale of air ambulance assets required to meet the one-hour evacuation goal across a noncontiguous area of operations. However, the “Golden Hour,” while grounded in sound medical principles, has become increasingly misaligned with the realities of LSCO and MDO. Much of Army doctrine still assumes permissive environments for evacuation, assumptions that no longer hold true in today’s contested and high-threat operational settings. As demonstrated in the ongoing conflict in Ukraine, evacuation often takes 24 hours or more due to operational constraints and the significant risks posed to evacuation crews. Initial casualty movement typically occurs on foot over several kilometers during the most critical window for survival, compounding delays to advanced care (1st International Legion Medical Services, Armed Forces of Ukraine, 2024).

Figure 1. Example evacuation zones in a noncontiguous area of operations (DA, 2025)
FM 3-04 Aviation Operations (DA, 2025) highlights the difficulty mission variables place on aeromedical evacuation element’s ability to achieve a one-hour evacuation standard within an area of operations.

Army medicine has shifted focus toward delivering appropriate medical care at the point of injury and through successive echelons to support PCC, recovery, and return-to-duty outcomes (Izaguirre et al., 2025; Center for Army Lessons Learned, 2025). Despite its original intent, the Gates directive and its incorporation into doctrine have blurred the line between physiological necessity and operational feasibility. While medical professionals regard the one-hour threshold as vital for preventing death from hemorrhage or shock, operational leaders often interpret it as a logistical benchmark for MEDEVAC response (Butler et al., 2020). In dispersed and contested environments, meeting this standard is rarely possible, resulting in delayed care and avoidable fatalities. The Ukraine conflict further underscores how emerging technologies and rapidly shifting mission dynamics contribute to high casualty rates while impeding consistent evacuation and access to surgical intervention (Brown et al., 2025; Izaguirre et al., 2025). This growing gap between doctrinal expectations and operational capability signals an urgent need to realign casualty evacuation planning with the complex demands of modern warfare. Figure 2 highlights the reality and intensity of PCC in LSCO.

Implications of the Golden Day

Leaders at all levels should communicate the consequences of operations in the form of risk mission and/or risk to force. In FOEs, where even a six-hour evacuation is optimistic, the term “Golden Day” implies a survivability buffer that often contradicts human biology (Dilday et al., 2024). In simple terms, more casualties will die in FOEs due to prolonged evacuation timelines. Shackelford et al. (2024) recently demonstrated that rapid surgical handoff remains directly correlated with improved patient outcomes, regardless of advancements in PCC. Similarly, Beldowicz, Bellamy, and Modlin (2020) caution that rigid timelines can hinder necessary innovation in mobile, farther-forward surgical care. These disparities reinforce the need for unified, doctrine-aligned definitions of trauma timelines to ensure operational leaders understand the implications of delays and the limits of modern medicine. At a minimum, efforts should aim to support informed, prudent, and ethical decision-making to prevent moral injury among leaders and Soldiers operating in PCC settings. As Pelkey (2024) highlights in the NCO Journal, a gap in triage training persists across the force, rooted in decades of reliable evacuation access. If unaddressed, this gap may contribute to moral injury, which undermines morale and increases the risk of depression and anxiety among service members. In LSCO environments, the triage, treatment, and evacuation decisions Soldiers make will inevitably affect their mental health and create further operational constraints

Figure 2. U.S. Army Medic Providing Care Under Fire
An AI-generated image (OpenAI, 2025) illustrating a Soldier tending to casualties inside a damaged urban structure while battle continues outside. The image highlights the intensity of prolonged casualty care in large-scale combat operations.

The Role and Limitations of Emerging Technologies

Technology continues to evolve as a critical enabler in medical modernization. Tools like remote monitoring, AI-supported decision-making, portable surgical units, advanced hemostatic agents, synthetic biological products, and telemedicine have expanded capabilities in austere environments (Defense Health Agency, 2022; U.S. Army Futures Command, 2022). These technologies can potentially extend survivability, especially when integrated into existing force structures and doctrinal training. However, technology is not a panacea. Tools must function within the unyielding constraints of human physiology. Without surgical intervention, even the most advanced technologies can only temporarily stabilize rather than save a life (Butler et al., 2020). For example, while portable ventilators and tele-guided procedures can buy time, they cannot resolve internal hemorrhage, a leading cause of preventable battlefield death (Eastridge et al., 2010). Emerging technologies must, therefore, be evaluated based on how well they extend care within physiological limits, not as a justification to replace or delay surgical response. Misplaced faith in technological solutions can create a false sense of capability that undermines operational planning and risks service members’ lives (Shackelford et al., 2024). While emerging technologies offer powerful tools to extend survivability, their effectiveness is contingent on timely application and well-trained personnel. Even the most advanced capabilities may prove ineffective or even harmful if not used correctly or appropriately (U.S. Army Futures Command, 2022).

Bridging the Gap: Innovation as a Force Multiplier

Innovation must be matched with realistic doctrine and robust training to maximize effectiveness. As Beldowicz et al. (2020) argue, the battlefield must be treated as a fluid continuum where mobile surgical teams, autonomous systems, and non-traditional medics work in tandem to close gaps between point of injury and definitive care.

Key areas of focus include:

• Doctrinal Alignment: Clearly defining “Golden Hour” and “Golden Day” as physiological versus logistical markers helps prevent confusion and improves casualty care planning (Johannigman, 2018; Dilday et al., 2024).
• Smart Investments: Prioritize funding, aligning, and fielding technologies, across Modified Tables of Organization and Equipment (MTOE), to extend survival windows rather than replace surgical necessity. These include prolonged care kits, rapid resuscitation systems, scalable surgical kits, enhanced telemedicine protocols, blood products and/or blood alternatives (Sallette, 2017; Izaguirre et al., 2025).
• Integrated Medical and Operational Training: Robust training must go beyond cross-disciplinary education for operational planners and include enhanced, scenario-specific preparation for medics and medical providers. Educating both tactical leaders and medical personnel on trauma physiology and care protocols fosters a shared understanding of capabilities and constraints, ensuring effective capability application in high-pressure, resource-constrained environments (Army Futures Command, 2022; Izaguirre & Thorson, 2025).
• Logistical Integration: PCC capabilities must be included in joint planning frameworks. Without integrated logistics and support, advanced technologies risk becoming burdensome or ineffective in FOEs (U.S. Army Futures Command, 2022).

Conclusion

To effectively preserve combat power in future engagements, the Army must reframe the “Golden Hour” as a dynamic operational principle, anchored not in rigid timelines but in adaptable medical capabilities, scalable evacuation strategies, and force readiness across all domains of conflict. This requires more than conceptual change: it demands concrete action. Doctrine must be updated to reflect realistic, flexible evacuation windows. Senior leaders should require Commanders to integrate delayed evacuation scenarios into tactical planning. PCC training must become a baseline competency for all soldiers, not a medical specialty. Additionally, the Army must prioritize aligning critical medical resources directly at the point of need to ensure timely, life-saving care under contested conditions. Through doctrinal clarity, targeted innovation, and cross-functional education, the Army can ensure that battlefield medicine remains responsive, responsible, and operationally relevant—preserving both life and lethality in future fights.