Cool First Transport Second: The Life-Saving Protocol for Exertional Heat Stroke

"Cool First, Transport Second" is the cardinal rule of prehospital medicine for exertional heat stroke. It means one simple, vital thing: cool the patient immediately on scene, before transporting them to hospital.

This protocol is now validated by the American College of Sports Medicine, the International Olympic Committee, and military health services worldwide. When correctly applied, it has reduced exertional heat stroke mortality from over 20% to near zero.

Why not transport first?

The historical mistake in exertional heat stroke management was to evacuate the patient to hospital as quickly as possible. This instinct, while logical, worsened outcomes for two reasons:

Transport time is lost treatment time. During transit, core temperature continues to rise — or at best plateaus — without effective cooling. Every minute above 40°C worsens brain, liver, and kidney damage.

Emergency departments are not always ready. Cold water immersion in a hospital setting requires specific preparation. Patients arriving too late and without pre-cooling have often exceeded the therapeutic window.

Dr Douglas Casa (Korey Stringer Institute, University of Connecticut) has documented this paradox across thousands of cases: patients rapidly transported without prior cooling had significantly higher mortality and disability rates than those cooled on scene, even when cooling began several minutes after collapse.

The scientific basis of the protocol

The Cool First Transport Second protocol rests on two fundamental physiological facts.

The 30-minute window. If core temperature returns below 40°C within 30 minutes of clinical presentation, survival rate is 100% in KSI-documented series. Beyond 30 minutes above 40°C, the risk of multi-organ failure increases exponentially.

The superiority of immersion. Cold water immersion cools at 0.35°C per minute. Alternative methods do not exceed 0.03°C per minute. To respect the 30-minute window starting from a temperature of 42°C, a cooling rate of at least 0.13°C/min is required — a threshold only immersion can reliably achieve in the field.

Practical protocol application

Step 1 — Recognition (0–2 minutes)

Any collapse during or immediately following intense physical exertion with:

Core temperature ≥ 40°C (tympanic or rectal)
Neurological signs: confusion, agitation, loss of consciousness, seizures

= Suspected exertional heat stroke — Cool First protocol activated immediately

Step 2 — Cooling (2–20 minutes)

Deploy the immersion tub, fill with cold water and ice, immerse the patient fully (shoulders and scalp), keep airway above water.

Continuous monitoring of rectal temperature every 5 minutes.

Step 3 — Call EMS (in parallel)

The call to emergency services is made in parallel with cooling, not before it. The dispatch message states: "Exertional heat stroke currently being treated by cold water immersion — requesting transport to emergency department once temperature returns below 38.6°C."

Step 4 — Stop cooling and transport

Remove the patient from the tub at 38.6°C rectal temperature. Do not wait for 37°C — risk of hypothermia by thermal inertia.

Transfer to emergency department for blood work (CPK, renal function, coagulation) and monitoring for secondary complications.

What the protocol changes for field teams

Before Cool First Transport Second, teams improvised with available means — wet towels, ice packs, fans. These methods created a false sense of security: the patient appeared to be receiving care while core temperature continued rising.

The protocol imposes a clear logistical requirement: a tub, water and ice must be available within 2 minutes at every at-risk intervention.

This is the logistical constraint Kollder solves. The cooling tub deployable in 30 seconds allows field teams — fire services, military medical units, event medical teams — to apply the protocol without any prior infrastructure.

Who needs to know this protocol?

Physicians and nurses in fire service medical units
Military medical officers
Event medical directors
EHS managers in exposed industries
Competition medical and rescue teams

The 2021 IOC consensus (Hosokawa, Racinais et al., BJSM) states that team training and equipment availability are the two non-negotiable conditions for protocol effectiveness.