What is the difference between heat stroke and heat exhaustion, and how are they treated?

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Last updated: July 6, 2025View editorial policy

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From the Guidelines

Heat stroke is a life-threatening emergency that requires immediate treatment, whereas heat exhaustion is a less severe condition that can be treated with rest, hydration, and cooling measures. The key difference between heat stroke and heat exhaustion lies in the severity of symptoms and the body's temperature regulation response. Heat exhaustion is characterized by heavy sweating, weakness, dizziness, nausea, headache, and a body temperature below 104°F (40°C), whereas heat stroke is marked by a body temperature above 104°F, altered mental status, confusion, seizures, and often hot, dry skin with minimal sweating 1.

Treatment Approaches

  • For heat exhaustion, treatment involves moving to a cool place, removing excess clothing, drinking cool water, and applying cool compresses, with most people recovering within 30 minutes with these measures 1.
  • Heat stroke, on the other hand, requires immediate emergency medical attention, with rapid cooling using ice packs, cold water immersion, or wet sheets with fans, and activation of emergency services 1.
  • The most recent guidelines recommend whole-body (neck-down) cool- to cold-water immersion for 15 minutes or until neurological symptoms resolve for both adults and children with heatstroke 1.
  • It is also reasonable to initiate 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 when water immersion is not available 1.

Importance of Prompt Treatment

The difference in severity between heat stroke and heat exhaustion stems from heat stroke involving failure of the body's temperature regulation system, which can quickly damage the brain, heart, kidneys, and muscles, potentially causing permanent disability or death if not treated promptly 1. Prompt recognition and treatment of heat stroke are critical to preventing long-term morbidity and mortality, with survival from heatstroke related to the speed at which temperature reduction is achieved; faster cooling is associated with better survival 1.

From the Research

Difference between Heat Stroke and Heat Exhaustion

  • Heat exhaustion occurs when the body loses too much water and salt, usually due to excessive sweating, and is characterized by symptoms such as malaise, vomiting, and confusion 2.
  • Heat stroke is a more severe condition that occurs when the body's temperature regulation fails, causing the core body temperature to exceed 40°C (104°F), and is characterized by symptoms such as cardiac arrhythmias, rhabdomyolysis, and serum chemistry abnormalities 2, 3.

Treatment of Heat Exhaustion

  • Treatment involves taking the affected person to a cool environment and replacing fluids and electrolytes if needed 2.
  • In more serious cases, intravenous hydration may be necessary, although monitoring of serum sodium levels is important to prevent cerebral edema 2.

Treatment of Heat Stroke

  • Heat stroke is a medical emergency that should be treated immediately with temperature-lowering techniques such as immersion in an ice bath or evaporative cooling 2, 4.
  • Fluid resuscitation is important but should be closely monitored, and renal function may need to be protected with mannitol and diuretics 2.
  • Aggressive cooling and management of life-threatening systemic complications, such as cardiac arrest, rhabdomyolysis, and acute renal failure, are essential to reduce morbidity and mortality 3.

Cooling Methods

  • Ice-water immersion has been shown to be highly effective in exertional heat stroke, with a zero fatality rate in large case series of younger, fit patients 4.
  • Evaporative plus convective cooling may be augmented by crushed ice or ice packs applied diffusely to the body, and chilled intravenous fluids may also supplement primary cooling 4.
  • It is important to continuously monitor core temperature during cooling treatment to avoid hypothermia 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Evaluation and treatment of heat-related illnesses.

American family physician, 2002

Research

Cooling Methods in Heat Stroke.

The Journal of emergency medicine, 2016

Research

Hypothermia following exertional heat stroke treatment.

European journal of applied physiology, 2011

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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