III. Types

  1. Classic Heatstroke
    1. Gradual environmental exposure
    2. Usually seen in elderly and debilitated patients
  2. Exertional Heatstroke
    1. Rapid onset over hours
    2. Usually seen in young patients and in athletes

IV. Signs

  1. Heat Exhaustion symptoms and signs
  2. Hyperpyrexia (Use rectal probe)
    1. Core Temperature exceeds 40 C (104 F) for Heat Stroke diagnosis
    2. Core temps may range as high as 44 C (111 F)
    3. Reports of Temperatures up to 47 C (116.6 F)
  3. Altered Level of Consciousness (Delirium or coma)
  4. Anhidrosis
  5. Tachycardia
  6. Hypotension
  7. Tachypnea

V. Labs

VI. Differential Diagnosis (hyperthermia with ALOC)

VII. Management

  1. Rapid cooling to Temperature under 101 F (38.3 C)
    1. See Evaporative Cooling
    2. Evaporative Cooling with fans and misting
    3. Cool saline bags applied to groin and axilla
    4. Ice water rectal enemas
    5. Ice water immersion (most effective measure)
      1. Associated with nearly 100% survival rate when used immediately in exertional Heat Stroke
      2. Casa (2007) Exerc Sport Sci Rev 35(3): 141-9 [PubMed]
    6. Nasogastric lavage
    7. Peritoneal lavage
  2. Same IV hydration as for Heat Exhaustion
    1. Observe closely for pulmonary edema
  3. ABC Management
    1. Intubation may be needed to protect airway
  4. Altered Level of Consciousness
    1. Treat as Delirium
    2. Check bedside Glucose
    3. Consider banana bag containing Thiamine
    4. Consider Naloxone
  5. Myoglobinuria
    1. Maintain urine output at 50 to 100 ml per hour
    2. Alkalinize urine and force diuresis with mannitol
  6. Disseminated Intravascular Coagulation (DIC)
    1. Fresh Frozen Plasma and platelets as needed
  7. Shivering with rapid cooling
    1. Consider Neuroleptics (e.g. Chlorpromazine)
    2. Dantrolene is not effective in lowering core temp
      1. Bouchama (2002) N Engl J Med 346:1978-88 [PubMed]

IX. Prognosis: Short-Term

  1. Mortality: <10% (if treated appropriately)
    1. Mortality higher in some groups (e.g. firefighters)
  2. Indicators of Poor Prognosis
    1. Core Temperature exceeds 42 degrees Celsius
    2. Aspartate Aminotransferase (AST) >1000 in first day
    3. Prolonged coma exceeds 2 hours

X. Prognosis: Long-Term outcomes for survivors

  1. Increased risk of Heat Stroke under same conditions
    1. Test heat tolerance 8-12 weeks post-episode
    2. Assess for residual injury in Thermoregulation
  2. Long-term neurologic or behavioral deficits
    1. Neurologic injury is permanent in 20% of cases
    2. Dematte (1998) Ann Intern Med 129:173-81 [PubMed]

XI. Prevention

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Ontology: Heat Stroke (C0018843)

Definition (MSH) A condition caused by the failure of body to dissipate heat in an excessively hot environment or during PHYSICAL EXERTION in a hot environment. Contrast to HEAT EXHAUSTION, the body temperature in heat stroke patient is dangerously high with red, hot skin accompanied by DELUSIONS; CONVULSIONS; or COMA. It can be a life-threatening emergency and is most common in infants and the elderly.
Concepts Injury or Poisoning (T037)
MSH D018883
ICD10 T67.0
SnomedCT 212938002, 269276002, 52072009
French COUP DE CHALEUR, Thermoplégie, Coup de chaleur
English HEAT STROKE, Heat Strokes, Heatstroke, Heatstrokes, Stroke, Heat, Strokes, Heat, Heat Stroke, Heat stroke, unspecified, heat stroke (diagnosis), heat apoplexy or hyperpyrexia, heat stroke, Heat Stroke [Disease/Finding], heat strokes, heatstroke, heat hyperpyrexia, heatstrokes, Heat stroke, unspecified (disorder), Overheating, Heat stroke, Heat apoplexy, Thermoplegia, Heat hyperpyrexia, Heat stroke (disorder), thermoplegia, heat; apoplexy, heat; hyperpyrexia, heat; stroke, hyperpyrexia; heat, stroke; heat, apoplexy; heat, Heat stroke, NOS
German HITZSCHLAG, Hitzschlag, Thermoplegie
Swedish Värmeslag
Japanese ネッシャビョウ, 熱中症, 渇病, 熱射病
Czech siriáza, úpal, Termoplegie, Úpal
Spanish Termoplejía, apoplejía por calor, apopejía por calor, insolación, no especificada, insolación, no especificada (trastorno), golpe de calor (trastorno), golpe de calor, termoplejía, Choque por calor, Golpe de Calor
Dutch thermoplegie, apoplexie; hitte, beroerte; hitte, hitte; apoplexie, hitte; beroerte, hitte; hyperpyrexie, hyperpyrexie; hitte, hitteberoerte, Steek, zonnen-, Zonnensteek
Portuguese Termoplegia, GOLPE DE CALOR, Intermação, Síncope Devida ao Calor, Golpe de calor, Golpe de Calor
Italian Termoplegia, Colpo di calore
Finnish Lämpöhalvaus
Polish Udar cieplny
Hungarian Thermoplegia, Hőguta
Norwegian Varmeslag, Heteslag, Termoplegi