Cool First, Transport Second: The History Behind Emergency Medicine's Field Cooling Doctrine

Most field protocols in emergency medicine accumulate gradually, refined by committee over years of incremental data. Cool First, Transport Second has a more specific origin: a preventable death in 2001, and the research career it set in motion.

August 2001

Korey Stringer, an offensive lineman for the Minnesota Vikings, died of exertional heat stroke during a preseason training camp practice in August 2001. He was 27. The death was widely covered, and preventable in the way that made it especially hard to accept: the warning signs of EHS are well documented, and were present.

His widow, Kelci Stringer, spent the following years working to make sure his death changed something. She brought in Douglas Casa, a University of Connecticut kinesiology researcher, as an expert witness in the litigation that followed. Casa had his own reason to take the case personally: he is himself a survivor of exertional heat stroke, first experiencing it decades earlier, and had already built a research career around the condition before Stringer's death.

From litigation to institute

That working relationship, sustained over roughly eight years, became the foundation for the Korey Stringer Institute (KSI), formally announced at the 2010 NFL Draft in partnership with Kelci Stringer, the NFL, and Gatorade. Casa became its CEO and chief researcher, housed at UConn's Department of Kinesiology, an institution already recognized as a national leader in heat and hydration research before KSI existed.

KSI's founding mission named three populations at risk: athletes, laborers, and warfighters, a scope that has shaped its research agenda ever since, from professional sport to military heat injury prevention to occupational heat exposure. The institute opened its MISSION Heat Lab in 2017 and has since worked directly with the NFL, the International Olympic Committee, World Athletics, FIFA, and the US military.

Building the evidence for cooling before transport

The doctrine that would become Cool First, Transport Second did not emerge from a single study. It accumulated from a specific, repeated clinical observation: patients who were cooled immediately on site, even by minutes, had dramatically better outcomes than patients who were stabilized and transported to a hospital first, even when that hospital was close by and equipped with advanced cooling technology.

The physiological explanation came into sharper focus with Casa's own 2007 review in Exercise and Sport Sciences Reviews, which quantified what many practitioners had observed anecdotally: whole-body cold water immersion cools at roughly 0.35°C per minute, compared to 0.03 to 0.05°C per minute for misting and fanning, and 0.10 to 0.15°C per minute for localized ice packs. That gap, multiplied across a 30-minute window, is the difference between resolving the emergency in the field and still being above a dangerous core temperature on hospital arrival.

Casa's personal clinical record reinforced the case: as of his most recent published figures, he has personally treated 295 documented cases of exertional heat stroke, with zero fatalities, using immediate on-site cold water immersion.

From clinical practice to formal consensus

What had been the practice of specialists like Casa gradually became formal medical consensus. The American College of Sports Medicine's Expert Consensus Statement on Exertional Heat Illness, most recently updated in 2023, and the International Olympic Committee's Adverse Weather Impact Expert Working Group statement (Hosokawa, Racinais et al., BJSM, 2021), both now state explicitly what KSI's clinical data had already shown: cooling takes priority over transport, full stop, for any suspected exertional heat stroke case.

The doctrine has since been written directly into operational standards for the professions most exposed to it. NFPA 1584, the US standard governing firefighter rehabilitation, names active cooling, including immersion methods, as a required step before a member returns to duty or is transported. Event medicine protocols for endurance sport, from marathons to Hyrox, now build medical post design around the same principle: cooling equipment has to be present at the point of collapse, not just at the ambulance.

What the doctrine requires operationally

A protocol is only as good as the equipment available to execute it. The entire premise of Cool First, Transport Second depends on cooling capability existing at the scene, immediately, not after a transport decision has already been made. That operational requirement, not the underlying science, is usually the actual bottleneck: cold water immersion is well understood and well proven, but it is only useful if a team can deploy it in the first minutes after collapse.

That gap between accepted protocol and field-deployable equipment is what the Kollder emergency cooling tub was built to close: full-body immersion, deployable in under 2 minutes by one person, anywhere the protocol needs to be executed. Teams building out their own Cool First capability can find specifications at kollder.com/#contact.