Heat Exhaustion and Heat Stroke

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Medical Author:

John P. Cunha, DO, FACOEP

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Heat Exhaustion and Heat Stroke Overview
• Heat Exhaustion and Heat Stroke Causes
• Heat Exhaustion and Heat Stroke Symptoms
• When to Seek Medical Care
• Heat Exhaustion and Heat Stroke Diagnosis
• Heat Exhaustion and Heat Stroke Treatment
• Heat Exhaustion and Heat Stroke Self-Care at Home
• Heat Exhaustion and Heat Stroke Medical Treatment
• Heat Exhaustion and Heat Stroke Follow-up
• Heat Exhaustion and Heat Stroke Prevention
• Heat Exhaustion and Heat Stroke Prognosis
• Synonyms and Keywords
• Author and Editor
• Read more on Heat Exhaustion and Heat Stroke from Healthwise

Heat Exhaustion and Heat Stroke Overview

Heat exhaustion: This condition often occurs when people exercise (work or play) in a hot, humid place and body fluids are lost through sweating, causing dehydration and overheating of the body. The person's temperature may be elevated, but not above 104 F (40 C).

Heat stroke: Heat stroke, also referred to as heatstroke or sun stroke, is a life-threatening medical condition. The person's cooling system, which is controlled by the brain, stops working and the internal body temperature rises to the point at which brain damage or damage to other internal organs may result (temperature may reach 105 F or greater [40.5 C or greater]).

Nearly 700 people die each year due to heat-related illness, according to the U.S. Centers for Disease Control and Prevention. Avoid heat exhaustion by not engaging in strenuous activity in hot, humid environments; and stay hydrated as prevention is the key.

Heat Exhaustion and Heat Stroke Causes

Heat exhaustion is typically caused when people who are not well adjusted to heat exercise or work in a hot, humid environment.

• At high temperatures, the body cools itself largely through evaporation of sweat.
  
  
• When it is very humid, this mechanism does not work properly.
  
  
• The body loses a combination of fluids and salts (electrolytes).
  
  
• When this is accompanied by an inadequate replacement of fluids, disturbances in the circulation may result that are similar to a mild form of shock.

Heat stroke may often develop rapidly.

• Medical conditions or medications that impair the body's ability to sweat may predispose people to this problem.
  
  
• Heat stroke happens in the following two ways:
  
  
  • The classic form occurs in people whose cooling mechanisms are impaired.
    
    
  • The exertional form occurs in previously healthy people who are undergoing strenuous activity in a hot environment.
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• Infants, children under the age of 4, the overweight, and the elderly are more likely to have this problem, as are those who are taking antihistamines and certain types of medication for high blood pressure, heart disease, or depression.