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Heat Exhaustion
Aka: Heat Exhaustion
- See Also
- Heat Illness
- Heat Edema
- Heat Cramps
- Heat Exhaustion
- Heat Stroke
- Temperature Regulation
- Heat Index
- Heat Illness Risk Factors
- Medications Predisposing to Heat Illness
- Heat Illness Prevention
- Mechanisms
- Dehydration
- Electrolyte loss
- Exercise-induced Respiratory Alkalosis
- Symptoms
- Fatigue
- Weakness
- Nausea and Vomiting
- Dizziness
- Myalgias
- Irritability
- Headache
- Dyspnea
- Signs
- Temperature increased between 100.4 F (38 C) to 104 F (40 C)
- Hypotension or Orthostasis
- Syncope
- Sweating
- Cutaneous Flushing
- Decreased urine output
- Mild neurologic changes
- Incoordination
- Confusion
- Irritability
- Mental status not seriously impaired
- Contrast with Heat Stroke
- Labs
- Evaluate for Rhabdomyolysis
- Urine blood positive on dipstick (but negative microscopy) suggests myoglobin
- Creatinine phosphokinase increased
- Normal Liver Function Tests (contrast with Heat Stroke)
- AST Normal
- ALT Normal
- LDH Normal
- Monitoring with fluid Resuscitation
- Serum Sodium
- Serum Potassium
- Serum phosphate
- Serum Calcium
- Serum Magnesium
- Management
- External cooling
- Cool environment
- Remove excess clothing
- Spray lukewarm water on body
- Cool with fans
- Gradual rehydration
- Manage Hypernatremia or Hyponatremia if present
- Manage Rhabdomyolysis if present
- Oral Rehydration (Mild cases)
- 1 Liter per hour over several hours
- Intravenous Rehydration
- Initial isotonic fluid replacement (NS or LR)
- Replace 50% total water deficit in first 3-6 hours
- Replace remaining 50% deficit over 6-9 hours
- Management: Playing field sideline
- Remove excess clothing
- Move to shaded environment
- Place supine with legs elevated
- Encourage oral fluids
- Obtain vital signs (be alert for Tachycardia or Hypotension)
- Persistent symptoms or signs >20 minutes should prompt emergency department care
- Prevention
- See Heat Illness Prevention
- References
- Czerkawski (1996) Your Patient Fitness 10(4): 13-20
- Sandor (1997) Physician SportsMed, 25(6):35-40
- Barrow (1998) Am Fam Physician 58(3):749-56
- Hett (1998) Postgrad Med 103(6):107-20
- Wexler (2002) Am Fam Physician 65(11):2307-20