Cooling Methods for Drug-Induced Hyperthermia: Systematic Review Insights for Emergency Care

Ice and Cold Water Immersion Are Most Effective for Drug-Induced Hyperthermia

Ice water and cold water immersion achieve the fastest and most reliable cooling rates for patients experiencing drug-induced hyperthermia, according to a systematic review published in October 2026 (OpenAlex W7220859227). The review synthesized data from 71 studies involving 1,932 patients and compared 12 cooling modalities. Ice water immersion cooled at an average rate of 0.169 ± 0.027 °C/min, while cold water immersion achieved 0.162 ± 0.037 °C/min. Both methods outperformed passive cooling and other techniques, such as room temperature immersion or evaporative methods, in reducing dangerously high body temperatures caused by stimulant intoxication and related emergencies.

Mechanisms, Context, and the Clinical Challenge of Drug-Induced Hyperthermia

Drug-induced hyperthermia is a life-threatening complication most commonly associated with stimulant drugs like cocaine and amphetamines, but also relevant to certain novel psychoactive substances. The condition arises when the body's heat production overwhelms its ability to dissipate heat, driving core temperatures above 39°C. Unlike exertional heat stroke, where hyperthermia improves when activity stops, stimulant-induced hyperthermia can persist due to ongoing central nervous system effects. This distinction means that even after cessation of drug use or physical activity, patients may remain at risk, complicating emergency management.

The review incorporated evidence from both drug-induced and exertional hyperthermia due to the scarcity of high-quality studies focused solely on intoxication cases. While both populations share overlapping demographics and risk factors, the underlying pathophysiology differs, which may affect the generalizability of some findings. Notably, the review found that practical constraints—such as the need for continuous patient monitoring and the logistical challenges of full-body immersion—often limit the use of the most effective cooling methods in real-world emergency and pre-hospital settings.

Policy, Protocol, and Research Implications for Acute Care

Current emergency protocols for hyperthermic intoxicated patients should prioritize ice or cold water immersion when feasible and safe, especially at large events or specialized facilities. However, for most emergency departments and pre-hospital teams, ice water-soaked sheets or towels represent a more practical and widely available alternative. This method offers a balance between cooling efficacy (0.121 ± 0.030 °C/min) and the ability to maintain continuous monitoring and address concurrent medical complications.

• Emergency medical services (EMS) and hospital administrators should review and update their protocols to reflect these findings, ensuring that staff are trained in rapid cooling techniques and that necessary supplies are available.
• Regulators and policymakers should recognize the evidence gap for drug-induced hyperthermia, particularly as the prevalence of novel psychoactive substances and high-potency stimulants increases.
• Future research should focus on randomized controlled trials and pragmatic studies in drug-induced cases, as well as on the feasibility and safety of combined or staged cooling strategies in diverse clinical environments.

One underappreciated challenge highlighted by the review is the difficulty of balancing aggressive cooling with patient safety, especially when patients are agitated, sedated, or have co-occurring complications such as rhabdomyolysis or cardiac instability. This complexity underscores the need for flexible, evidence-informed protocols rather than rigid, one-size-fits-all guidelines.

Risks, Unknowns, and the Need for Targeted Data

The review notes that while immersion techniques are the gold standard for rapid cooling, their use can be limited by resource constraints, patient agitation, and the risk of complications such as aspiration or arrhythmia. There is also a lack of high-certainty data specifically for drug-induced hyperthermia, with most evidence extrapolated from exertional heat stroke or mixed populations. This introduces uncertainty regarding optimal cooling rates, thresholds for intervention, and the management of patients with overlapping toxicities or comorbidities.

For substances with less well-characterized hyperthermic risk profiles—including some psychedelics and novel synthetic drugs—there is an urgent need for targeted surveillance and research. Emergency clinicians should maintain a high index of suspicion for hyperthermia in intoxicated patients, even when classic stimulants are not involved, and should be prepared to escalate to the most effective available cooling methods as clinical circumstances allow.

Looking Forward: Preparing for Emerging Drug Risks and Acute Care Demands

As the landscape of recreational and synthetic drug use evolves, the incidence and complexity of drug-induced hyperthermia presentations may increase, placing new demands on pre-hospital and emergency care systems. This systematic review provides a clear hierarchy of cooling interventions but also exposes critical evidence gaps and operational barriers that must be addressed through coordinated research, training, and policy development.

Clinicians, researchers, and policymakers should prioritize the collection of prospective data on drug-induced hyperthermia and the evaluation of cooling strategies in real-world settings. In the interim, emergency protocols should emphasize rapid recognition, aggressive cooling with the most effective and feasible methods, and ongoing monitoring for complications. The development of adaptable, context-sensitive protocols will be essential as new psychoactive substances with unpredictable risk profiles continue to emerge.

Byline: Dr. Alex J. Marsh, MD, MPH. Reviewed by Dr. Alex J. Marsh on 2026-10-08. Research based on direct review of the systematic review published in OpenAlex W7220859227 and primary clinical guidelines.