MedicineNet.com
About Us | Privacy Policy | Site Map
November 24, 2009
MedicineNet home Picture Slideshows Diseases and conditions Symptoms and signs Procedures and tests Medications Health and Living Picture Image Collection MedTerms medical dictionary
Font Size
A
A
A


Hyperthermia and Heat-Related Illness

Medical Author: Steven Doerr, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

What is hyperthermia?

Hyperthermia is overheating of the body. The word is made up of "hyper" (high) + "thermia" from the Greek word "thermes" (heat). Hyperthermia is literally high heat. There are a variety of heat-related illnesses, including heat stroke and heat exhaustion. Other heat-related health problems include heat cramps, heat rash and sunburn.

Summer can bring heat waves with unusually high temperatures that last for days and sometimes weeks. In the summer of 1980, a severe heat wave hit the United States, and nearly 1,700 people lost their lives from heat-related illness. Likewise, in the summer of 2003, tens of thousands of people died of the heat in Europe. High temperatures put people at risk.

What causes hyperthermia and heat-related illnesses?

People suffer heat-related illness when the body's temperature control system is overloaded. The body normally cools itself by sweating. But under some conditions, sweating just isn't enough. In such cases, a person's body temperature rises rapidly. Very high body temperatures can damage the brain or other vital organs.

Several factors affect the body's ability to cool itself during extremely hot weather. When the humidity is high, sweat will not evaporate as quickly, preventing the body from releasing heat quickly. Other conditions that can limit the ability to regulate temperature include old age, obesity, fever, dehydration, heart disease, poor circulation, sunburn, and drug, and alcohol use.

Those at greatest risk of heat-related illness include:

  • infants and children up to four years of age

  • people 65 years of age or older

  • people who are overweight

  • people who overexert during work or exercise

  • people who are ill or on certain medications

Infants and children up to four years of age are very sensitive to the effects of high temperatures and rely on others to regulate their environments and provide adequate liquids.

People 65 years of age or older may not compensate for heat stress efficiently, and are less likely to sense and respond to changes in temperature.

Overweight people may be prone to heat sickness because of their tendency to retain more body heat.

Any health condition that causes dehydration makes the body more susceptible to heat-related illness. If you or someone you know is at higher risk, it is important to drink plenty of fluids, avoid overexertion, and get your doctor or pharmacist's advice about medications being taken for:



Next: Hot weather health emergencies »

Printer-Friendly Format  |  Email to a Friend


Suggested Reading by Our Doctors
MedicineNet Doctors
  • Rash - Learn about rash causes, symptoms, diagnosis and treatment. Common skin rashes include poison ivy, hives, shingles, eczema, contact dermatitis, ringworm, psoriasis and impetigo.
  • Dehydration - Read about dehydration (definition: excessive water loss) in children, treatment, symptoms (thirst, dry mouth, dark urine) and causes (vomiting, diarrhea).
  • Muscle Spasms - Read about muscle spasms, their causes, diagnosis, treatment and prevention. Symptoms and signs include acute pain at the site of the muscle contractions (twitches or fasciculations).

Latest Medical News



Women's Health

Find out what women really need.


Are you Depressed? Take the Quiz

Your Guide to Symptoms & Signs: Pinpoint Your Pain



Hyperthermia

Introduction to heat exhaustion

Heat exhaustion is a milder form of heat-related illness that can develop after several days of exposure to high temperatures and inadequate or unbalanced replacement of fluids. Those most prone to heat exhaustion are elderly people, people with high blood pressure, and people working or exercising in a hot environment.

Heat exhaustion symptoms

Warning signs of heat exhaustion include:

  • heavy sweating
  • paleness
  • muscle cramps
  • tiredness
  • weakness
  • dizziness
  • headache
  • nausea or vomiting
  • fainting

The skin may be cool and moist. The victim's pulse rate will be fast and weak, and breathing will be fast and shallow. If heat exhaustion is untreated, it may progress to heat stroke, which is a medical emergency. Seek medical attention and call 911 immediately if:...

Read the Heat Exhaustion article »










Health categories:

Slideshows | Diseases & Conditions | Symptoms & Signs | Procedures & Tests | Medications | Health & Living | News & Views | Medical Dictionary

Popular health centers:

Allergies | Arthritis | Cancer | Diabetes | Digestion | Healthy Kids | Heart | Men's Health | Mental Health | Women's Health | More...

Publications:

ePublications (PDFs) | XML News via RSS | Audio Podcasts | Email Newsletters

MedicineNet.com:

About Us | Privacy Policy | Site Map | WebMD® | Medscape® | eMedicine® | eMedicineHealth® | RxList®

This website is certified by Health On the Net Foundation. Click to verify. This site complies to the HONcode standard for trustworthy health information:
verify here.

©1996-2009 MedicineNet, Inc. All rights reserved. Notices and Legal Disclaimer.
MedicineNet does not provide medical advice, diagnosis or treatment. See additional information.