What are the presentation, signs, symptoms, and management of heat stroke (Hyperthermia)?

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Last updated: April 10, 2025View editorial policy

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From the Guidelines

Heat stroke is a life-threatening emergency that requires immediate action, and the most effective management strategy is to move the individual from the hot environment, remove excess clothing, limit exertion, and provide cool liquids if the person is able to swallow, as recommended by the 2024 American Heart Association and American Red Cross guidelines for first aid 1. The key signs and symptoms of heat stroke include high body temperature, altered mental status (confusion, delirium, seizures, or coma), hot and dry or sweaty skin, rapid breathing, racing heart rate, headache, nausea, and vomiting. Heat stroke has two main types: exertional (occurring during physical activity) and non-exertional (affecting elderly or chronically ill individuals during heat waves).

Management Strategies

  • Remove the person from the heat source and call emergency services immediately, as heatstroke is a medical emergency that requires rapid cooling, intravenous fluids, and intensive monitoring and support in a hospital setting 1.
  • Rapid cooling is essential, and initiating immediate active cooling by using whole-body (neck-down) cool- to cold-water immersion for 15 minutes or until neurological symptoms resolve (whichever occurs first) is a reasonable approach for adults and children with heatstroke, as recommended by the 2024 American Heart Association and American Red Cross guidelines for first aid 1.
  • Other forms of active cooling, including commercial ice packs, cold showers, ice sheets and towels, cooling vests and jackets, and evaporative, fanning, or a combination of techniques, can be used when water immersion is not available 1.
  • Monitor vital signs continuously and administer intravenous fluids (normal saline) to correct dehydration and electrolyte imbalances.
  • Benzodiazepines like diazepam (5-10mg IV) may be needed for seizures, and medications that impair sweating or temperature regulation like anticholinergics should be avoided.
  • Hospital management includes continued cooling until core temperature reaches 38-39°C, monitoring for complications like rhabdomyolysis, acute kidney injury, liver failure, and disseminated intravascular coagulation.

Prevention Strategies

  • Gradual acclimatization to hot environments, proper hydration, wearing loose-fitting clothing, and avoiding outdoor activities during peak heat hours can help prevent heat stroke.
  • The target core temperature to cool until is 39° C (102.2° F), and it may be reasonable for first aid providers, who are trained and willing, to measure core temperature during active cooling for heatstroke, as recommended by the 2024 American Heart Association and American Red Cross guidelines for first aid 1.

From the Research

Heat Stroke Presentation

  • Heat stroke is a serious and potentially life-threatening condition defined as a core body temperature >40.6 degrees C 2
  • Two forms of heat stroke are recognized: classic heat stroke and exertional heat stroke, with different demographics and risk factors 2
  • Clinical manifestations of heat stroke include extreme fatigue, hot dry skin or heavy perspiration, nausea, vomiting, diarrhea, disorientation, dizziness, uncoordinated movements, and reddened face 2

Signs and Symptoms

  • Elevated body temperature and neurologic dysfunction are necessary but not sufficient to diagnose heat stroke 2
  • Associated clinical manifestations such as extreme fatigue, hot dry skin or heavy perspiration, nausea, vomiting, diarrhea, disorientation, dizziness, uncoordinated movements, and reddened face are frequently observed 2
  • Heat stroke can lead to severe complications such as end-organ damage and death 3

Management

  • Immediate cooling and support of organ-system function are the two main therapeutic objectives in patients with heat stroke 4
  • Immersion in an ice-water bath is the most effective cooling method, and evaporative cooling is a rapid and effective alternative 4, 5, 6
  • Aggressive IV rehydration should be continued for the first 24 to 72 hours to prevent the development of rhabdomyolysis-induced acute renal failure 4
  • Water immersion techniques (using 1-17°C water) more effectively lower core body temperatures when compared with passive cooling, in hyperthermic adults 5
  • A body bag for cold-water immersion can be used if a bath is not available, as a unique technique in community emergency departments 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Heat stroke: a comprehensive review.

AACN clinical issues, 2004

Research

[Treatment of heat stroke].

Nihon rinsho. Japanese journal of clinical medicine, 2012

Research

Heat stroke : a review of cooling methods.

Sports medicine (Auckland, N.Z.), 2004

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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