Heatstroke causes, symptoms: Hydration and sunburn protection are some preventive measures

Heatstroke is a serious and potentially fatal condition caused by the body's inability to regulate its temperature, often due to prolonged exposure to high temperatures or intense physical exertion in hot, humid environments. This condition, also known as sunstroke, is the most severe form of hyperthermia, characterised by a core body temperature exceeding 104 degrees Fahrenheit (40 degrees Celsius). Without prompt treatment, heatstroke can lead to severe complications such as brain damage, organ failure, or even death.

Types of heatstroke: There are two main types of heatstroke exertional and non-exertional.

Exertional heatstroke: This type is caused by vigorous physical activity in hot conditions and can develop within a few hours, says Dr Rameshwar Kala from Felix Regale hopsital, Secunderabad. He says that it is most commonly seen in athletes, soldiers, and laborers who engage in strenuous activities under high temperatures.

Non-exertional (Classic) heatstroke: This type generally affects vulnerable populations such as the elderly or individuals with underlying health conditions, says Kala. It develops over several days of prolonged heat exposure without significant physical exertion.

Heat exhaustion vs. heatstroke: Heat exhaustion is a milder condition that can precede heatstroke. It does not cause neurological issues and is typically not life-threatening. However, if left untreated, heat exhaustion can progress to heatstroke.

Who are at high risk: Certain populations are more susceptible to heatstroke. These include infants and the elderly, who have a reduced ability to regulate body temperature. Other risk factors, according to Kala, include:

• Dehydration
• Alcohol consumption
• Certain medications (e.g., diuretics, sedatives, blood pressure medications)
• Medical conditions that affect sweating (such as cystic fibrosis)
• Wearing heavy clothing
• Obesity
• Poor physical conditioning
• A history of previous heatstroke

Causes of heatstroke: Heatstroke occurs when the body cannot effectively dissipate heat, causing an unsafe rise in core temperature. The hypothalamus, which regulates body temperature, fails to maintain the normal set-point of 98.6 degrees Fahrenheit (37 degrees Celsius) under extreme heat stress, leading to a dangerous increase in internal temperature, says Kala.

Symptoms of heatstroke: 

• Extremely high body temperature (above 104 degrees Fahrenheit)
• Altered mental state or behavior (e.g., confusion, agitation, delirium, or seizures)
• Hot and dry skin
• Rapid breathing
• Racing heart rate
• Headache
• Nausea and vomiting
• Unconsciousness in severe cases

Complications of heatstroke:

• Shock
• Coma
• Acute respiratory distress syndrome (ARDS)
• Brain swelling
• Kidney and liver failure
• Metabolic dysfunction
• Nerve damage
• Circulatory problems

Diagnosis and treatment: Diagnosing heatstroke usually occurs in an emergency setting and involves reviewing symptoms, performing a physical examination, and measuring body temperature. Additional tests, such as blood tests, urinalysis, chest X-rays, or electrocardiograms, may be used to determine the extent of organ damage.

Treatment focuses on rapid cooling of the body. First-aid measures include:

• Moving the person to a cool, shaded area
• Applying ice packs to the neck, groin, and armpits
• Encouraging the intake of slightly salted fluids
• Immersing the person in cool water
• Misting with water while fanning
• Removing tight or heavy clothing

At the hospital, treatments might involve intravenous cooled fluids, cooling blankets, ice baths, seizure prevention medication, and supplemental oxygen. In severe cases, cold-water lavage might be necessary.

Preventing heatstroke:

• Avoiding strenuous activity in hot weather
• Staying hydrated with sports drinks or lightly salted water
• Gradually acclimating to hot conditions
• Wearing lightweight, light-colored, and loose-fitting clothing
• Protecting against sunburn
• Never leaving anyone in a parked car