What is the management for exercise-induced hyperthermia and fatigue in an 8-year-old male?

Management of Exercise-Induced Hyperthermia and Fatigue in an 8-Year-Old Male

Immediately assess for exertional heat stroke by checking for altered mental status, CNS dysfunction, or core temperature ≥40°C (104°F), and if present, initiate rapid whole-body cooling on-site without delay while activating emergency medical services. 1

Immediate Assessment and Triage

Determine severity by evaluating for CNS abnormalities:

• Check for altered mental status, delirium, confusion, seizures, or loss of consciousness—these indicate exertional heat stroke requiring emergency intervention 1, 2
• Assess for signs of heat exhaustion: weakness, dizziness, nausea, syncope, headache with core temperature <40°C (104°F) 1
• Move the child immediately to shade and remove all protective equipment, uniforms, and excess clothing 1

Measure core temperature when feasible:

• Rectal temperature is the gold standard and should be checked by trained personnel if available 1
• However, do not delay treatment waiting for temperature verification if moderate to severe heat stress symptoms are present 1

Acute Management Based on Severity

For Exertional Heat Stroke (Core Temperature ≥40°C or CNS Dysfunction)

Activate EMS immediately and begin aggressive cooling:

• Cold- or ice-water immersion is the preferred and most effective cooling method 1
• Alternative if immersion unavailable: Apply ice packs to neck, axillae, and groin; rotate ice-water-soaked towels to all other body areas 1
• Continue cooling until rectal temperature reaches just under 39°C (approximately 102°F) or clinical improvement occurs 1
• This represents a life-threatening emergency with significant morbidity and mortality risk if not treated promptly 1, 2

For Heat Exhaustion (Moderate Heat Illness)

Initiate prompt rapid cooling for 10-15 minutes:

• Move to shade, remove excess clothing and equipment 1
• Apply cooling measures (ice packs, wet towels, fans) 1
• If alert enough to ingest fluids, begin oral hydration immediately 1
• Monitor closely for progression to heat stroke 1

Hydration Management

For an 8-year-old, provide 100-250 mL (approximately 3-8 oz) of fluid every 20 minutes:

• Water is sufficient for most cases of heat exhaustion 1
• Consider electrolyte-supplemented beverages emphasizing sodium if exercise duration was ≥1 hour or in hot weather conditions with extensive sweat loss 1
• Avoid overdrinking, which can lead to hyponatremia 1

Return to Activity Restrictions

The child must not return to any physical activity for the remainder of the current session, regardless of symptom improvement 1

Critical Pitfalls to Avoid

• Never delay cooling while waiting for temperature measurement or EMS arrival—begin on-site cooling immediately 1
• Do not use aspirin in children due to Reye syndrome risk 2
• Recognize that children with adequate hydration have similar thermoregulatory capacity as adults, so hyperthermia indicates modifiable risk factors were present (excessive exertion, insufficient recovery, inappropriate clothing/equipment) 1
• Be aware that recent illness (especially with fever, vomiting, or diarrhea) significantly increases heat illness risk 1

Underlying Pathophysiology Considerations

Exercise-induced hyperthermia causes central fatigue through excessive heat storage in the brain, leading to impaired motor activation and reduced neural drive from the CNS 3, 4, 5. The fatigue involves inhibitory signals from the hypothalamus secondary to elevated brain temperature and altered dopaminergic neurotransmitter activity 4, 5. Reduced cerebral blood flow during exercise with hyperthermia (approximately 20% reduction) impairs heat removal from the brain, contributing to heat storage and central fatigue 6.