Heat Stroke vs. Heat Exhaustion: Know the Difference

When the power fails in a heat wave, there’s no air conditioning and people overheat. Learn to tell these two conditions apart: one needs rest and water, the other can kill within hours.

Heat exhaustion

Signs: heavy sweating; cold, pale, clammy skin; fast, weak pulse; nausea or vomiting; muscle cramps; tiredness or weakness; dizziness; headache; fainting.

What to do:

• Move to a cooler place.
• Loosen clothing.
• Apply cool, wet cloths, or take a cool bath.
• Sip water.

Get medical help right away if the person is vomiting, their symptoms get worse, or their symptoms last longer than an hour.

Heat stroke: a medical emergency

Signs: body temperature of 103°F (39.4°C) or higher; hot, red skin, dry or damp; fast, strong pulse; headache; dizziness; nausea; confusion; passing out.

What to do:

1. Call 911 right away.
2. Move the person to a cooler place.
3. Lower their temperature with cool cloths or a cool bath.
4. Do not give them anything to drink.

The key differences: heat exhaustion usually means cool, clammy skin and a weak pulse, while heat stroke means hot skin, a strong pulse and a confused mind.

Prevention when the power is out

Drink water regularly before you feel thirsty, rest in the shade during the hottest hours, wet your clothing and skin, and check often on older adults, children and anyone sick. Store extra water for hot weather: needs can double. See how much water to store.