Heat-Related Hazards: Heat Cramps, Heat Exhaustion, Heat Stroke, and Hyponatremia

Heat Cramps

Often caused by a lack of salt in the body, and usually affect people who sweat a lot during strenuous activity. Low salt level in the muscles causes painful cramps. Heat cramps are usually the earliest symptom of the spectrum of heat‐related illness.

• Symptoms: profuse sweating, involuntary muscle spasms
• Treatment: Stop the activity being performed, get to a cooler location, drink plenty of fluids, and gently stretch and massage the muscles that are cramping.

Heat Exhaustion

The result of dehydration due to intense sweating. Hikers can lose one or two quarts (liters) of water per hour.

• Symptoms: pale face, nausea, vomiting, cool and moist skin, headache, cramps
• Treatment: Drink water with electrolytes, eat high‐energy foods (with fats and sugars), rest in the shade for 30 to 45 minutes, and cool the body by getting wet.

Heatstroke

A life‐threatening emergency where the body's heat regulating mechanisms become overwhelmed by a combination of internal heat production and environmental demands. Your body loses its ability to cool itself.

• Symptoms: flushed face, dry skin, weak and rapid pulse, high core body temperature, confusion, poor judgment or inability to cope, unconsciousness, seizures
• Treatment: The heatstroke victim must be cooled immediately! Continuously pour water on the victim's head and torso; fan to create an evaporative cooling effect. Immerse the victim in cold water if possible. Move the victim to shade and remove excess clothing. The victim needs evacuation to a hospital. Someone should go for help while attempts to cool the victim continue.

Hyponatremia (water intoxication)

An illness that mimics the early symptoms of heat exhaustion. It is the result of low sodium in the blood caused by drinking too much water and losing too much salt through sweating.

• Symptoms: nausea, vomiting, altered mental states, confusion and frequent urination. The victim may appear intoxicated. In extreme cases, seizures may occur.
• Treatment: Have the victim eat salty foods, slowly drink sports drinks with electrolytes, and rest in the shade. If mental alertness decreases, seek immediate help.