1. Heat Rash Slideshow Pictures
2. Summer Skin Hazards Slideshow Pictures
3. Dehydration Tips Slideshow Pictures

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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In this Article

• Heat rash facts
• What is heat rash?
• What are the causes of heat rash?
• What are the symptoms of heat rash in children and adults?
• What does heat rash look like?
• Heat rash pictures
• Who is at risk for heat rash?
• How is heat rash diagnosed?
• What is the treatment for heat rash?
• Home remedies for heat rash
• Medical treatment for heat rash
• How can heat rash be prevented?
• How effective are electric fans in preventing heat rash?
• How can people protect their health when temperatures are extremely high?
• How much water should I drink in hot weather?
• Should I take salt tablets during hot weather?
• What is the best clothing to wear in hot weather or a heat wave?
• What is the prognosis for heat rash?
• Pictures of Heat Rash - Slideshow
• Pictures of Summer Skin Hazards - Slideshow
• Pictures of Dehydration Tips - Slideshow
• Patient Comments: Heat Rash - Causes
• Patient Comments: Heat Rash - Treatment
• Patient Comments: Heat Rash - Symptoms
• Patient Comments: Heat Rash - Describe Your Experience
• Find a local Doctor in your town
• Heat Rash Index

The body can adapt very well in hot weather, but it takes time to acclimate. The actual temperature is just one factor when a person decides to work, play, or exercise in the heat. The heat index adds humidity to the equation since sweat cannot evaporate if the water content in the air (humidity) is high. If the air holds as much water as it can there is no place for sweat to go, and evaporation cannot cool the body.

To minimize the risk of  heat-related illnesses, try to avoid working or exercising in extreme heat. Avoid dehydration and other complications by taking frequent breaks to get out of the heat, and drinking plenty of water or other fluids to replenish fluid lost through sweat.

Early signs of heat-related illnesses include lightheadedness, weakness, and nausea. It is important to get out of the heat, cool off, and rehydrate immediately to avoid severe heat-related problems such as heat exhaustion and heat stroke.

To calculate the heat index in your area, check out the U.S. Army's Heat Index Calculator.

It is hard to gauge how much water is lost through sweat, and the thirst mechanism may not be sensitive enough to remind a person to drink enough. In general, the kidneys are a good guide to whether there is enough water in the body. If the body is dehydrated, the kidneys will try to hold on to as much water as possible. Decreased urine production, urine concentrated in color, and a strong urine odor are signs that the kidneys are trying to conserve the body's water supply. Urine is clear when there is enough fluid in the body.

In a hot environment, a person should drink enough water to make the urine clear, and make sure the body is producing sweat. Sweat and urine loss also involves electrolyte loss. Although drinking water is good, other fluids such as sports drinks should also be consumed to replace lost electrolytes to avoid other problems like hypokalemia (low potassium). People that are taking medications for conditions such as diabetes, kidney problems, and congestive heart failure (CHF) need to be especially careful about their fluid intake, and discuss how to avoid hot-weather related problems with their doctor(s).