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Heat-related Illness (Hyperthermia)

A man shields his head from the sun as he walks across the Brooklyn Bridge on a hot summer day in New York City.

The human body is great at cooling itself through natural mechanisms, but extreme heat can overwhelm the body, resulting in heat-related illness.

Heat-related illness can include:

  • Heat cramps

  • Heat exhaustion

  • Heat stroke

Older adults, young children and people with chronic medical conditions are at high-risk for heat-related illness. Hundreds of people in the U.S. die every year of heat-related illness.

When you visit your national forests and grasslands, take the extra time to protect yourself and others from heat related illness.

  • Drink plenty of water. Avoid sugary drinks and alcohol, as they can lead to dehydration.

  • Stay in the shade whenever possible

  • Schedule the most rigorous activities for early or later in the day

  • Wear lightweight, loose-fitting, light-colored clothing

  • Keep a close eye on older adults, children, and those with chronic medical conditions

Heat Exhaustion

  • Heavy sweating

  • Weakness

  • Cold, pale, clammy skin

  • Fast, weak pulse

  • Nausea or vomiting

  • Fainting

What to do

  • Move to a cooler location

  • Lie down and loosen clothing

  • Apply cool, wet cloths to as much of the body as possible

  • Sip water

  • If vomiting occurs and continues, seek medical attention immediately

Heat Stroke

  • Heat stroke is a medical emergency. If you suspect heat stroke or see the signs below, call 911 immediately.

  • High body temperature (above 103°F)

  • Red, hot, dry, or moist skin

  • Rapid, strong pulse

  • Unconsciousness

What to do:

  • Call 911 immediately

  • Move to a cooler environment

  • Reduce body temperature with cool cloths or with a cool bath

  • Do NOT give fluids