Heat Exhaustion
NOTICE: This page is written by medical professionals solely for the use of NCC Ride Leaders in case of an emergency. If in doubt, immediately call 911 for professional assistance.
Heat exhaustion is a condition that develops during prolonged exposure to heat. It is more likely to occur during strenuous activity, such as exercise or manual labor. Symptoms include a fast heartbeat, excess sweating, extreme tiredness, muscle cramps, headache, and weakness. They may also include stomach cramps, nausea, and vomiting. The person may be lightheaded and dizzy, and may even faint.
Treatment for heat exhaustion involves cooling the body down and replacing lost fluids, electrolytes, and salts. Cooling may be done with fans, cold cloths, or a cold-water bath. Fluids are best replaced by drinking electrolyte solution, a sports drink, or water with 2 teaspoons of salt added for each 8 ounces. If a person is very dehydrated, confused, or unable to drink, IV (intravenous) fluids will likely be needed.
Heat exhaustion can progress to a serious condition called heatstroke, so it should be treated right away.
When to seek medical advice: Call your healthcare provider right away for any of the following:
- Inability to keep fluids down
- Vomiting
- Worsening symptoms or new symptoms
When to Call 911: Call 911 or emergency services right away for any of these symptoms of heatstroke:
- Confusion
- Irrational behavior
- Hallucinations
- Trouble walking
- Seizures
- Vomiting or diarrhea
- Hot, flushed skin
- Passing out
- Fever of 104°F (40°C) or higher
Even severe heat stress can appear suddenly, so learn the warning signs and how to treat them.
Mild – Heat Stress: Core body temperature stays at 98.6°F (37°C). It isn’t dangerous unless the symptoms aren’t treated. Signs and symptoms include:
- Sweating a lot
- Having painful spasms in your muscles during activity or hours afterward (heat cramps)
- Developing tiny red bumps on skin and a prickling sensation (prickly heat)
- Feeling irritable or weak
Get medical advice and do the following:
- Rest in a cool, shady area.
- Drink water or a sport drink.
Moderate – Heat Exhaustion: Core body temperature may rise up to 101°F (38.3°C). It should be treated right away. Signs and symptoms include:
- Sweating a lot
- Cold, moist, pale or flushed skin
- Feeling very weak or tired
- Headache, nausea, loss of appetite
- Feeling dizzy or giddy
- Rapid or weak pulse
Get medical treatment urgently. You may be told to:
- Rest in a cool, shady area.
- Drink water or a sport drink. In some cases, a medical professional must administer fluids.
- Take salt (in some cases).
- Use cool compresses on the forehead, around the neck, and under armpits.
- Blow air onto your skin with fans.
Severe – Heat Stroke: This is a serious, life-threatening medical emergency. Core body temperature can rise to 105°F (40.5°C) or more. If not treated right away, heat stroke can lead to permanent brain damage and even death. Signs and symptoms include:
- Hot, dry skin that looks red, mottled, or bluish
- Deep, fast breathing
- Headache or nausea
- Rapid, weak, or irregular pulse
- Feeling dizzy, confused, or delirious
- Fainting
- Convulsions
Treatment: Someone should call for emergency help right away. While waiting for emergency help, the affected person should:
- Rest in a cool, shady area.
- Have clothing soaked with cool water. Or, remove outer clothing and be wrapped with a sheet soaked in cool water. Place the person in water in a tub or children’s swimming pool if available.
- Be cooled with fans.
- Drink water or a sport drink. Do not try to give a drink to someone who is unconscious.
