What are the symptoms and treatment of heat stroke (Hyperthermia)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 12, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Heat stroke is a severe medical emergency that requires immediate action, and the most effective treatment is rapid cooling, intravenous fluids, and intensive monitoring and support in a hospital setting. The symptoms of heat stroke include confusion, lack of sweating despite heat, rapid heartbeat, headache, nausea, and unconsciousness, and it occurs when body temperature rises above 104°F (40°C) due to prolonged exposure to high temperatures or physical exertion in hot weather 1. If you suspect heat stroke, call emergency services right away and move the person to a cooler location. Remove excess clothing and cool the body with cold water, ice packs on the neck, armpits, and groin, or immersion in cold water if possible, as recommended by the 2024 American Heart Association and American Red Cross guidelines for first aid 1.

Key Recommendations

  • Move the individual from the hot environment and remove excess clothing to help lower body temperature 1
  • Provide cool liquids if the person is able to swallow, but do not give medications as they may interfere with the body's ability to regulate temperature 1
  • Activate emergency services for people with heatstroke (heat illness with altered mental status) 1
  • Initiate immediate active cooling using whole-body cool- to cold-water immersion for 15 minutes or until neurological symptoms resolve, or use other forms of active cooling such as commercial ice packs, cold showers, or evaporative cooling when water immersion is not available 1

Prevention and High-Risk Groups

People at higher risk of heat stroke include the elderly, young children, those with chronic illnesses, and individuals taking certain medications like diuretics or antipsychotics. Prevention involves staying hydrated, avoiding outdoor activities during peak heat, wearing lightweight clothing, and acclimatizing gradually to hot environments. Without prompt treatment, heat stroke can cause organ damage or death, emphasizing the importance of rapid cooling and medical attention 1.

From the Research

Symptoms of Heat Stroke

  • Elevated body temperature 2
  • Central nervous system dysfunction 2
  • Hyperthermia (>40 °C/>104 °F) 3
  • Nervous system dysregulation 3

Treatment of Heat Stroke

  • Aggressive cooling [(2,4,5,6,3)]
  • Management of life-threatening systemic complications 2
  • External cooling devices 2
  • Immersion in an ice-water bath [(4,6,3)]
  • Evaporative cooling [(4,6,3)]
  • Ice pack application 6
  • Pharmacological treatment 6
  • Invasive techniques 6
  • IV rehydration 4
  • Fluid and salt replacement 4
  • Rest in a cool environment 4
  • IV magnesium sulphate to relieve muscle cramping 4
  • Body bag filled with cold water and ice as an alternative to cold-water immersion 5

Cooling Methods

  • Immersion in water at different temperatures 6
  • Evaporative cooling 6
  • Ice pack application 6
  • Pharmacological treatment 6
  • Invasive techniques 6
  • Water immersion techniques (using 1-17 °C water) 3
  • Passive cooling 3

Important Considerations

  • Early recognition and treatment are essential to reduce morbidity and mortality 2
  • Rapid cooling should be initiated immediately at the time of collapse 6
  • Cooling should be based on feasible field measures, including ice or tepid water 6
  • Management should be matched to the patient's age and medical background 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Heat Stroke: A Medical Emergency Appearing in New Regions.

Case reports in critical care, 2017

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.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.