Written by Ketan Patel
Spoon Feed
Implementation of a prehospital cold water immersion (CWI) strategy in a large urban EMS system was effective in rapid cooling with associated neurological improvement and high survival rates.
Breaking the ice before hitting the ED
The events, sports, and military spheres have established CWI as the gold standard in rapid cooling for heat stroke patients, but this hasn’t gained much traction in the prehospital setting.
This study asked whether a systemwide prehospital CWI protocol for adult heat stroke is feasible and associated with effective temperature reduction and favorable outcomes. In a retrospective, multisite observational cohort of 183 patients treated by Phoenix Fire Department in 2024, median prehospital immersion was 13.5 minutes; 72.1% had temperature decrease from field to ED (mean −2.0 ± 1.5°C). Overall mortality was 19.1%, and 69.4% were discharged neurologically intact (GCS 15).
The retrospective uncontrolled design limits interpretation, as well as a reliance on peripheral (tympanic) field temperatures and GCS as surrogate outcomes. The multicenter approach also leads to potential documentation and selection biases, with potential limited generalizability beyond a single, urban, high‑heat EMS environment with relatively short transport times.
How will this change my practice?
Here in Las Vegas, one of our prehospital partners in the county uses CWI, but a large subset of our population lacks access to this technique, not only in the prehospital realm but in the Emergency Department. Findings from this study can help with implementation of a CWI protocol while mitigating obstacles for more widespread and effective adoption in the right patient and EMS settings.
Source
Fighting Fire with Ice: A Multisite Collaboration to Evaluate the Impact of Prehospital Cold Water Immersion on Heat Stroke Patients. Prehosp Emerg Care. 2026 Mar 13:1-11. doi: 10.1080/10903127.2026.2636148. Epub ahead of print. PMID: 41739962.
