What are the symptoms and treatment of heat exhaustion?

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From the Guidelines

Heat exhaustion symptoms include nausea, dizziness, muscle cramps, feeling faint, headache, fatigue, and heavy sweating, and if suspected, immediate action should be taken to move to a cool place, stop physical activity, and cool down, as indicated by the 2024 American Heart Association and American Red Cross guidelines for first aid 1.

Symptoms of Heat Exhaustion

The symptoms of heat exhaustion may start suddenly and include:

  • Nausea
  • Dizziness
  • Muscle cramps
  • Feeling faint
  • Headache
  • Fatigue
  • Heavy sweating These symptoms are caused by a combination of exercise-induced heat and fluid and electrolyte loss as sweat, as noted in the 2010 American Heart Association and American Red Cross guidelines for first aid 1.

Treatment of Heat Exhaustion

If heat exhaustion is suspected, the following steps should be taken:

  • Move to a cool place
  • Stop physical activity
  • Cool down by removing excess clothing and providing 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
  • Apply cool, wet cloths to the body or take a cool bath
  • Drink water or a sports drink like Gatorade to rehydrate and replace lost electrolytes If symptoms do not improve within an hour, worsen, or include confusion or loss of consciousness, seek medical help immediately, as this may indicate heat stroke, which is life-threatening, as emphasized in the 2024 American Heart Association and American Red Cross guidelines for first aid 1.

Prevention of Heat Exhaustion

Prevention of heat exhaustion includes:

  • Staying hydrated
  • Wearing lightweight clothing
  • Avoiding midday heat
  • Acclimatizing gradually to hot environments
  • Adjusting exercise to the weather, as recommended by the 2001 American Heart Association exercise standards for testing and training 1 It is essential to be aware of the symptoms of heat exhaustion and take prompt action to prevent it from progressing to heat stroke, which can be fatal, as highlighted in the 2024 American Heart Association and American Red Cross guidelines for first aid 1.

From the Research

Heat Exhaustion Symptoms

  • Heat exhaustion is characterized by symptoms such as malaise, vomiting, and confusion 2
  • Early warning signs of heat exhaustion include flushed face, hyperventilation, headache, dizziness, nausea, tingling arms, piloerection, chilliness, incoordination, and confusion 3
  • Heat exhaustion can occur suddenly or over time, and can be worsened by dehydration due to inadequate access to water or insufficient fluid replacement 4

Treatment of Heat Exhaustion

  • Treatment involves taking the affected person to a cool environment and replacing fluids and electrolytes if needed 2
  • Mild cooling, rest, and hydration are recommended for heat exhaustion 5
  • In more extreme situations, more aggressive cooling strategies (e.g., cold shower, application of wet towels) to lower core temperature should be employed 4
  • Intravenous hydration may be necessary in more serious cases, although monitoring of serum sodium levels is important to prevent cerebral edema 2

Prevention of Heat-Related Illnesses

  • Increasing public awareness of the risks associated with exposure to high temperatures and prolonged exercise can help prevent heat-related illnesses 4
  • Acclimatization, adequate hydration, and avoidance of activities during extreme heat are the most effective measures to reduce the incidence of heat-related illnesses 5
  • Tips to avoiding heat illness include: rely not on thirst, drink on schedule, favor sports drinks, monitor weight, watch urine, shun caffeine and alcohol, key on meals for fluids and salt, stay cool when you can, and know the early warning signs of heat illness 3

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

Treatment of suspected heat illness.

International journal of sports medicine, 1998

Research

Heat exhaustion.

Handbook of clinical neurology, 2018

Research

Heat-Related Illnesses.

American family physician, 2019

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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