Heat Illness

On this page

Basics

• Summary
• Start Here
• Symptoms
• Prevention and Risk Factors
• Treatments and Therapies

Learn More

• Related Issues
• Specifics

See, Play and Learn

• Videos and Tutorials

Research

• Clinical Trials
• Journal Articles

Resources

• Find an Expert

For You

• Children
• Seniors
• Patient Handouts

Summary

Your body normally cools itself by sweating. During hot weather, especially with high humidity, sweating just isn't enough. Your body temperature can rise to dangerous levels and you can develop a heat illness. Most heat illnesses occur from staying out in the heat too long. Exercising too much for your age and physical condition are also factors. Older adults, young children and those who are sick or overweight are most at risk. Drinking fluids to prevent dehydration, replenishing salt and minerals, and limiting time in the heat can help.

Heat-related illnesses include

• Heatstroke - a life-threatening illness in which body temperature may rise above 106° F in minutes; symptoms include dry skin, rapid, strong pulse and dizziness
• Heat exhaustion - an illness that can precede heatstroke; symptoms include heavy sweating, rapid breathing and a fast, weak pulse
• Heat cramps - muscle pains or spasms that happen during heavy exercise
• Heat rash - skin irritation from excessive sweating

Centers for Disease Control and Prevention

Start Here

• Extreme Heat (Department of Homeland Security) Also in Spanish
• Frequently Asked Questions (FAQ) about Extreme Heat (Centers for Disease Control and Prevention)
• Hyperthermia: Too Hot for Your Health (National Institute on Aging) Also in Spanish

Symptoms

• Warning Signs and Symptoms of Heat-Related Illness (Centers for Disease Control and Prevention) Also in Spanish

Prevention and Risk Factors

• Extreme Heat: A Prevention Guide to Promote Your Personal Health and Safety (Centers for Disease Control and Prevention)
• Heat Wave Safety Checklist (American Red Cross) - PDF

Treatments and Therapies

• Heat Cramps, First Aid (Logical Images)
• Heat Exhaustion, First Aid (Logical Images)
• Heatstroke, First Aid (Logical Images)

Related Issues

• Fitness: Stay safe during hot-weather exercise (Mayo Foundation for Medical Education and Research)
• Protect Your Heart in the Heat (American Heart Association)

Specifics

• Heat Exhaustion and Heatstroke (American Academy of Family Physicians) Also in Spanish
• Heat Stress (National Institute for Occupational Safety and Health)
• Heat Waves (Healthy Roads Media) - PDF Also in Spanish
• Miliaria Rubra (Logical Images)

Videos and Tutorials

• Children in Hot Cars Result in Fatal Consequences (American College of Emergency Physicians)
• Heat Waves (Healthy Roads Media) Also in Spanish
• Heat-Related Illnesses (American College of Emergency Physicians)

Clinical Trials

• ClinicalTrials.gov: Dehydration (National Institutes of Health)
• ClinicalTrials.gov: Heat Stress Disorders (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Mitigating Exertional Heat Illness in Military Personnel: The Science Behind...
• Article: Excess mortality during the warm summer of 2015 in Switzerland.
• Article: How resilient is the general population to heatwaves? A knowledge...
• Heat Illness -- see more articles

Find an Expert

• American Red Cross Also in Spanish
• Centers for Disease Control and Prevention Also in Spanish
• National Center for Environmental Health (Centers for Disease Control and Prevention)
• National Institute for Occupational Safety and Health Also in Spanish
• National Institute on Aging Also in Spanish

Children

• Miliaria Rubra (Logical Images)
• Parents' and Coaches' Guide to Dehydration and Other Heat Illnesses in Children (National Athletic Trainers' Association) - PDF Also in Spanish

Seniors

• Exercising Safely in Hot Weather (National Institute on Aging) - PDF
• Heat Stress in Older Adults (Centers for Disease Control and Prevention)
• Hyperthermia: Too Hot for Your Health (National Institute on Aging) Also in Spanish

Patient Handouts

• Heat emergencies (Medical Encyclopedia) Also in Spanish
• How to avoid overheating during exercise (Medical Encyclopedia) Also in Spanish
• Protecting Workers from Heat Stress (Occupational Safety and Health Administration)
• Protecting Yourself from Heat Stress (National Institute for Occupational Safety and Health) - PDF Also in Spanish