What is the treatment for exertional heat stroke (EHS) and heat exhaustion (HE)?

Treatment of Exertional Heat Stroke and Heat Exhaustion

For exertional heat stroke (EHS), immediate active cooling using whole-body (neck-down) cold-water immersion is the most effective treatment until core temperature reaches <39°C or neurological symptoms resolve. 1

Distinguishing Heat Exhaustion from Heat Stroke

Heat Exhaustion

• Moderate heat illness characterized by:
  • Weakness, dizziness, nausea, syncope, headache
  • Core temperature ≤40°C (104°F)
  • No central nervous system dysfunction
  • Inability to maintain blood pressure and cardiac output

Heat Stroke

• Severe multi-system heat illness characterized by:
  • Core temperature ≥40°C (104°F)
  • Central nervous system abnormalities (altered mental status, delirium, convulsions, coma)
  • Potential organ dysfunction and tissue damage

Treatment Algorithm

Immediate First Aid for Both Conditions

1. Move the person from the hot environment
2. Remove excess clothing
3. Limit physical exertion
4. Provide cool liquids if the person is conscious and able to swallow 1

For Heat Exhaustion

• Implement the immediate first aid measures above
• Place in shade or air-conditioned environment
• Monitor for progression to heat stroke

For Heat Stroke (Medical Emergency)

1. Activate emergency services immediately 1
2. Begin rapid cooling without delay (do not wait for diagnostic procedures) 2
3. Implement cooling in order of effectiveness:
   • First choice: Whole-body (neck-down) cold-water immersion (1-26°C/33.8-78.8°F) 1
   • If immersion not available: Use alternative active cooling methods 1:
     • Commercial ice packs to neck, axillae, and groin
     • Cold showers
     • Ice sheets and towels
     • Cooling vests and jackets
     • Evaporative cooling with water spray and fanning
4. Continue cooling until:
   • Core temperature reaches <39°C (102.2°F) OR
   • Neurological symptoms resolve OR
   • 15 minutes have elapsed (for initial field treatment) 1
5. Monitor core temperature during cooling if trained and equipment available 1

Evidence-Based Cooling Rates

• Cold-water immersion: Fastest cooling rate (approximately 0.2°C/min) 1, 3
• Commercial ice packs: 0.13-0.18°C/min when applied to facial cheeks, palms, and soles 1
• Cold shower (20.8°C): 0.03°C/min 1
• Temperate water immersion (≥20°C): 0.11±0.06°C/min (acceptable but not ideal) 3

Special Considerations

Children

• Similar approach to adults with immediate active cooling
• Cold-water immersion is recommended as first-line treatment
• Alternative cooling methods if immersion is not available 1

Hemodynamically Unstable Patients

• Evaporative cooling methods may be better tolerated than immersion 2
• Position safely to prevent aspiration
• Secure airway if altered consciousness is present 2

Potential Complications and Monitoring

• Monitor for:
  • Rhabdomyolysis
  • Acute kidney injury
  • Disseminated intravascular coagulation
  • Hepatic injury
  • Electrolyte abnormalities 2, 4

Common Pitfalls to Avoid

• Delaying cooling - This is the most critical error; cooling should begin immediately 2
• Relying on antipyretics - Medications like aspirin and acetaminophen are ineffective and may worsen liver injury 2
• Discontinuing cooling too early - Continue until target temperature or symptom resolution 2
• Failing to monitor for multi-organ dysfunction after initial cooling 2
• Using ice packs only at strategic locations (neck, axilla, groin) as the primary cooling method - This is less effective than whole-body cooling 5

Remember that exertional heat stroke is a true medical emergency where "time is tissue" - rapid recognition and cooling are essential for survival and to minimize organ damage 6.