Heat Stroke: Symptoms and Treatment

Heat Stroke: Symptoms and Treatment

Heat stroke is the 

most serious form of 

heat injury and is a 

medical emergency. If 

you suspect that 

someone has heat 

stroke -- also known 

as sunstroke -- you 

should call 911 

immediately and 

render first aid until 

paramedics arrive.

Heat stroke can kill or cause damage to the brain and other 

internal organs. Although heat stroke mainly affects people 

over age 50, it also takes a toll on healthy young athletes.

Heat stroke often occurs as a progression from milder heat-

related illnesses such as heat cramps, heat syncope 

(fainting), and heat exhaustion. But it can strike even if you 

have no previous signs of heat injury.

Heat stroke results from prolonged exposure to high 

temperatures -- usually in combination with dehydration 

-- which leads to failure of the body's temperature control 

system. The medical definition of heat stroke is a core body 

temperature greater than 105 degrees Fahrenheit, with 

complications involving the central nervous system that occur 

after exposure to high temperatures. Other common 

symptoms include nausea, seizures, confusion,

 disorientation, and sometimes loss of consciousness or 

coma.

Symptoms of Heat Stroke

• extremely high core temperature of up to 41°C (106°F)
• hot, red, dry skin
• rapid pulse
• rapid, shallow breathing
• headache
• confusion, strange behaviour
• possible loss of consciousness

Someone with heat stroke has stopped sweating, due to a failure in his or her heat control system.

High core temperatures damage the internal organs, especially the brain. The fluid loss can also produce dangerously low blood pressure. Most people who are killed by heat stroke die when their heart stops pumping effectively (circulatory failure). Even people who survive are likely to have permanent brain damage if their core temperature has been over 40.6°C (105°F) for more than an hour or two.

Treatment for  Heat Stroke

Heat stroke is a medical emergency. Learn to recognize the symptoms listed above and take the appropriate action. The heat stroke victim needs to see a doctor as soon as possible, but the first step is to get the core temperature under control.

If you suspect someone has heat stroke, begin treating them immediately while someone else calls 9-1-1. Everything must be done to cool the heat stroke victim immediately. The best solution is to remove them from the sun, immerse the body in cold water, such as a river, stream, or bathtub. Otherwise, remove most of their clothes, douse them with water, and fan them vigorously. Wrapping in wet sheets can help increase the rate of heat loss. If the person is conscious and alert, offer him or her water or other fluids. Avoid caffeinated or alcoholic drinks because they dehydrate you.

If the victim starts shivering, slow down the cooling treatment because shivering raises core temperature. Take the person's temperature every 10 minutes if you have a thermometer handy. You should not let the core temperature fall below 38°C (100°F), as this can result in an uncontrollable slide towards dangerously low temperatures (hypothermia). All the while you should be making arrangements to get the victim to an emergency room. Watch for signs of respiratory arrest (breathing failure) and be ready to give mouth-to-mouth resuscitation (rescue breathing).

The heat exhaustion victim should also be put in a cool place. Lay them down and give small gulps of liquid every few minutes. "Sports" drinks are best but water is often more readily available. You should watch carefully for signs of deterioration, but there's no need to rush to a hospital for a normal case of heat exhaustion.

The way to prevent these problems is to drink very large amounts of liquid during heat waves, especially if you're planning on working or exercising outdoors. If exercising, approximately 500 mL to 1.8 L of water should be consumed in the 3 hours before the activity with about 200 mL to 250 mL consumed every 20 minutes during the activity. Fluid loss continues after the activity is over, so it is important to continue to consume water for several hours after exercise. Some experts suggest continuing until urine is pale in colour.

You shouldn't take salt tablets unless you're also drinking a lot of water. When in very hot environments, drink every hour whether you feel like it or not, since thirst is a late indicator of dehydration. To prevent heat stroke:

• Avoid heavy outdoor activities in the summer during the hottest times of the day.
• Wear loose-fitting, light-coloured clothes - light colours reflect more sunlight.
• Try to relax in the shade during the hottest part of the day.
• Avoid coffee and alcohol, especially beer, due to their fluid loss effect.
• Learn the technique of mouth-to-mouth resuscitation.