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What is Heatstroke?

Due to the scorching hot weather in many areas of Thailand and tropical countries, heatstroke is a condition you should be aware of and concerned about. When you exercise or do strenuous physical activities in hot and humid weather and not drinking enough water, your body temperature can become too high, leading to heatstroke. Babies, young children, older adults, or people with health conditions are at higher risk of developing heatstroke even without doing any intense physical activities.

Heatstroke is a medical emergency that can lead to severe complications such as organ failure, damage, or even death if there is a delay in the diagnosis and treatment.

Type of heatstroke

• Exertional heatstroke is secondary to doing strenuous physical activity in hot weather.
• Nonexertional or classic heatstroke is due to prolonged exposure to hot and humid weather. Older adults or people with chronic illnesses are susceptible to this heatstroke type.

Symptoms

• Core body temperatures, such as ear and rectal temperature of 40 degrees Celsius or higher
• Alteration in behavior or mental status, including confusion, irritability, trouble speaking, delirium, seizures, or coma. 
• Dry and hot skin if the heatstroke is from hot weather. 
• Dry and slightly moist skin if the heatstroke is from intense exercise.
• Nausea and vomiting.
• Skin blushing.
• Racing heartbeats and shallow and rapid breathing
• Throbbing headache

When to see a doctor

If you find someone with heatstroke or think you are having a heatstroke, in Thailand call 1669 for an ambulance. While waiting, immediately cool off that person by taking him/her indoors or under a shade, taking off excess clothing, placing ice packs or wet towels on the head, neck, armpits, and groin, or spraying, sponging, or soaking him/her with cold water.

Causes

• Hot, humid weather.
• Exercise or do intense physical activities in hot, humid weather.
• Wear non-breathable or thick clothes so your sweat cannot evaporate, preventing your body from cooling off.
• Not drinking enough water.
• Alcoholic beverages can interfere with how your body controls the temperature.

Risk factors

• The central nervous system of very young children is underdeveloped and deteriorates in older adults. Both age groups tend to drink inadequate water. Therefore, they are at higher risk of developing heatstroke.
• Sudden heat or sun exposure, especially for people not acclimated to hot weather.
• Prolonged strenuous physical activities such as running a marathon, playing football, or under military training 
• Medications such as diuretics, vasoconstrictors, beta-blockers, antidepressants, or ADHD stimulants
• A history of heatstroke or preexisting chronic diseases such as heart or lung disease and obesity

Complications

prompt and appropriate treatment, heatstroke can cause swelling and permanent damage to vital organs such as the brain, heart, kidneys, and other organs, or even death.

Prevention

Heatstroke is preventable. You can stay safe in hot weather by following these steps.

• Avoid prolonged heat exposure, especially if it is over 40 degrees Celsius.
• Protect your skin from the sun with sunscreen with SPF 15 or higher, a wide-brimmed hat, and sunglasses. Reapply sunscreen every 2 hours or more often if you are sweating or swimming.
• Wear light, breathable, and loose-fitting clothes. 
• Drink water often
• Refrain from doing strenuous activities or exercising in hot weather. If possible, do it in the early morning or evening instead.
• Limit your time in the hot weather if you have just arrived in a country with a hot climate. People not acclimated to hot weather are prone to develop a heat-related illnesses. 
• Never leave your child or pet in a parked car in warm weather because the in-car temperature can increase by more than 11 degrees Celsius in 10 minutes. Parking the car in the shade or opening the car’s windows is not sufficient to prevent heatstroke.
• Be cautious if you are on medications or have a condition that can cause a higher risk of developing heatstroke.

Diagnosis

Heatstroke is usually evident from the physical examination. However, corroboration with laboratory tests for organ damage and ruling out other possible causes are indicated. 

• Rectal temperature is a more reliable way to check body temperature than oral and ear temperatures. 
• Blood tests evaluate organ damage by obtaining blood gases, electrolytes, liver enzymes, clotting studies, etc.
• A urine test to assess if your kidney or muscle is affected; a heat-related illness usually causes the urine to be darker.
• Muscle function tests measuring creatine kinase can determine if you develop rhabdomyolysis or muscle damage.
• A brain imaging study to rule out other suspected central nervous system causes of altered mental status. 

Treatment of heatstroke

Your doctor will try to lower your body temperature to prevent or minimize brain and vital organ damage. 

• Cold water immersion lowers your body temperature and decreases the risk of organ damage and death.
• Evaporation cooling technique, spraying cold mist on your body while directing airflow from a fan to you to hasten evaporation, cooling off your skin.
• Wrapping a cooling blanket around you and placing ice packs on your neck, back, armpits, and groin 
• A muscle relaxant to control shivering, when your body temperature is lower by the afore-mentioned treatment, your body will start to quiver to increase the temperature, making the treatment less effective.

Home remedies

If you have a heatstroke, immediately call for an ambulance because home treatment may be futile. Refrain from drinking liquids while waiting.

If you have heat exhaustion or heat-related illness, which do not require emergency care, you can try to lower your body temperature to prevent the progression as follows:

• Lower your body temperature with a damp cloth, cool water spray, or fan.
• Take a cold bath or shower. Soak in a stream or river if you are outdoors. 
• Go to a cool shady area or place with air-conditioning, like a mall.
• Drink plenty of water or sports drinks to replenish salts and water. 
• Avoid icy cold drinks, which can cause stomach cramps, and sugary and alcoholic beverages, which may interfere with how your body regulates temperature. 

Article by
Dr Rapeephan R.Maude

A doctor specializing in infectious disease
Doctor profile