Exertional Heat Illness T67.0XXA 992.0


synonyms:heat stroke, heat exhaustion, dehydration, heat illness

Heat Illness ICD-10

Heat Illness ICD-9

  • 992.0 Heat stroke and sunstroke  Heat apoplexy  Heat pyrexia   ictus

Heat Illness Etiology / Epidemiology / Natural History

  • Heat stroke: 10% mortality
  • Heat cramps may be related to dehydration, diet poor in minerals, large sodium/electrolyte losses in sweat.
  • Heat transfer to the environment occurs through conduction, convection, evaporation, and radiation. 
  • Evaporation of sweat is the primary mechanism regulating core temperature when the ambient temperature exceeds 35°C.  (High humidity inhibits sweat evaporation)

Heat Illness Anatomy

Heat Illness Clinical Evaluation

  • Heat cramps: muscle cramps, intense muscle pain.
  • Heat Exhaustion: heat cramps with headache, weakness/fatigue, skin pale and moist, syncope, ataxia, incoordination, profuse sweating, no CNS changes.
  • Heat stroked: Warm to the touch, no visible sweating, altered consciousness, coma, convulsions, disorientation, irrational behavior, irritability, confusion, combativeness. Tachycardia, hypotension, tachypnea. Confusion, delirium and bizzare behavior are often first signs
  • Heat-related illness is defined as a core temperature above 40°C.

Heat Illness Xray / Diagnositc Tests

  • Heat stoke = Rectal temperature >104°
  • Heat Illness Risk Assessment: best done with Web bulb globe thermometer (WBGT); <65°F(18°C)=low risk; 65°-73°F (18°-23°C)=moderate risk; 73°-82°F (23°-28°C)=high; >82°F(28°C)=Extreme risk.

Heat Stroke Classification / Treatment

  • Heat Cramps: move to cool dry place, rehydrate with carbohydrate/electrolyte containing sports drink.
  • Heat Exhaustion: loosen clothing, apply ice to axilla and groin, drink cool water, cool water sprays, prop legs up.
  • Heat Stroke: IV fluids and cooling. Immediate immersion in an ice water bath is the quickest and most efficent method of cooling. Consider also: cool water sprays, fans, ice bags in groin/axilla/neck. Transfer to ER ASAP.

Heat Illness Associated Injuries / Differential Diagnosis

  • Hyponatremia
  • Stroke
  • GI illness

Heat Stroke Complications

  • Death: 10%
  • End organ damage
  • Hemodynamic collapse

Heat Illness Follow-up Care

  • Prevention: maintain hydration, gradual acclimation to heat, avoid strenous exercise on high and extreme risk days.
  • Heat stroke: no strenous exercise for at least 1 week with gradual return to activity after.

Heat Illness Review References

  • Seto CK, Clin Sports Med 2005;21:695
  • Smith JE, Br J Sports Med 2005;39:503
  • Griffin LY, JBJS 2005;87:894
  • Noonan B, Bancroft RW, Dines JS, Bedi A. Heat- and cold-induced injuries in athletes: evaluation and management. J Am Acad Orthop Surg. 2012 Dec;20(12):744-54.
  • Howe AS, Boden BP. Heat-related illness in athletes. Am J Sports Med. 2007 Aug;35(8):1384-95.
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