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Heat stroke

Last reviewed: 28 Oct 2023
Last updated: 16 Jun 2020



History and exam

Key diagnostic factors

  • profound central nervous system disturbance
  • hyperthermia
More key diagnostic factors

Other diagnostic factors

  • headache
  • nausea and vomiting
  • anxiety
  • dizziness
  • tachycardia
  • jaundice
  • muscle tenderness
  • hypotension
  • gastrointestinal bleeding
  • bruising and skin bleeding
Other diagnostic factors

Risk factors

  • older age
  • impaired cognition
  • patients unable to care for themselves
  • medications
  • people who are unacclimatized to hot environments
  • young, active people exercising intensely under hot, humid conditions
More risk factors

Diagnostic investigations

1st investigations to order

  • core temperature measurement
  • serum electrolytes
  • CBC
  • LFTs
  • metabolic profile
  • renal function tests
  • creatine kinase
  • prothrombin time, activated PPT, and INR
  • lactic acid
  • urinalysis
  • chest x-ray
  • arterial blood gas
  • medication/toxicology screen
  • thyroid function tests
  • plasma glucose
More 1st investigations to order

Investigations to consider

  • cranial CT scan
  • lumbar puncture
  • blood culture
More investigations to consider

Treatment algorithm


heat exhaustion

heat stroke



James L. Glazer, MD, FACSM, CAQSM

Assistant Professor

Tufts University School of Medicine




JLG declares that he has no competing interests.

Peer reviewers

Martin Bocks, MD

Clinical Lecturer

University of Michigan Congenital Heart Center

Ann Arbor



MB declares that he has no competing interests.

James Milledge, MBBS

Honorary Professor

Department of Physiology




JM declares that he has no competing interests.

Paul Hamilton, MD


Department of Emergency Medicine

Mount Sinai School of Medicine

New York



PH declares that he has no competing interests.

  • Differentials

    • Delirium
    • Meningitis
    • Diabetic ketoacidosis
    More Differentials
  • Guidelines

    • National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses
    • Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Heat-Related Illness: 2014 Update
    More Guidelines
  • Patient leaflets

    Heat stroke

    More Patient leaflets
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