How to Identify Heat Stroke – Treatment and Prevention
Introduction
Our body has various heat dissipation mechanisms, such as evaporation, convection, conduction and radiation, controlled by a central thermostat located in the preoptic nucleus of the anterior hypothalamus and the central nervous system.
Heat stroke is a life-threatening condition in which the body overheats to dangerously high levels (>40°C) as the cooling mechanisms of the body fail. The body can get overheated due to strenuous exercise or exposure to high temperatures. Heat stroke requires immediate attention as prolonged high body temperatures increase the risk of organ damage (brain, muscles, kidneys and heart) or even death.
Types of heat stroke
Non-exertional or classic heat stroke occurs due to prolonged exposure to high temperatures, such as a heat wave. It is common in vulnerable populations (older adults, infants and those with chronic medical conditions).
Exertional heat stroke occurs when strenuous physical activity is performed in hot or humid conditions. It is commonly found in athletes or labourers who engage in intense activity without adequate hydration.
Identifying heat stroke
It is important to recognise the early warning signs of heat stroke, which may present initially as heat exhaustion. Heat exhaustion is less severe than heat stroke and presents with the following symptoms:
- Heavy sweating
- Fatigue
- Dizziness
- Muscle cramps
- Headache
- Nausea
- Vomiting
Symptoms of heat stroke
- An elevated body temperature (> 40°C)
- Some individuals may experience no sweating and have dry, red skin, and others may experience profuse sweating; both conditions indicate the body’s inability to cool down.
- Brain function is affected, leading to irritability, slurred speech, confusion, hallucinations, ataxia (lack of coordination in voluntary movements), seizures or unconsciousness
- The heart beats faster to circulate the blood rapidly and cool the body
- Upset stomach, leading to vomiting
- Severe headache
- Electrolyte imbalance leading to muscle cramps and weakness
Complications of heat stroke
- Nervous system (confusion, seizures, coma or permanent brain damage)
- Circulatory system (irregular heartbeat, hypotension or cardiac arrest)
- Muscular system (Rhabdomyolysis [muscle damage releases proteins into the bloodstream, causing kidney failure])
- Kidneys (low blood pressure, dehydration and muscle breakdown can damage the kidneys, and they may cease to function)
- Liver inflammation
- Disseminated intravascular coagulation (DIC), a condition where blood clots are formed in the entire body, causing organ damage and bleeding.
- Pulmonary oedema (fluid in the lungs)
- Multiorgan failure; if prompt treatment is not provided, it can lead to death
Treatment of heat stroke
Heat stroke requires immediate attention, with treatment being initiated before reaching the hospital.
Immediate first aid
- Remove the patient immediately from the hot environment, move to a cool, shaded area and call for HELP (044 4000-6000)
- Remove excess clothing
- Apply icepacks to the neck, armpit and groin
- Accelerate cooling by spraying water and providing airflow using a fan
- Elevate feet (improves circulation and lowers core body temperature)
What you should avoid:
Fever-reducing medicine, such as acetaminophen, should not be administered as it can worsen complications, including organ damage. No fluids should be administered as there is a risk of fluid aspiration. Fluids should be offered only if the person is conscious and can swallow. Do not give caffeinated beverages as they cause dehydration.
Medical treatment
In the hospital, the main focus is cooling the body until it reaches a safe temperature.
- Intravenous fluids are administered to cool and rehydrate the body and at a rate that ensures adequate urine output.
- The function of the brain, kidneys and heart is monitored.
- Oxygen therapy is given if breathing is affected.
- Medications to control symptoms if necessary
- Cooling techniques: Various techniques are used to cool the body as mentioned below.
- Cold water immersion: A cold-water bath is effective in lowering the body temperature and attaining core body temperature. A person experiencing a heat stroke must receive cold water immersion (cover the extremities and keep the head out) as soon as possible to reduce the risk of organ damage.
- Cooling by evaporation: Cool water is sprayed on the body, and warm air is blown over the person. Water evaporates and cools the skin.
- Cooling blankets or ice packs: The person is covered in a cooling blanket or ice packs are placed in the groin region, neck or armpits.
- Medication for shivering: If treatments to reduce the body temperature cause shivering, benzodiazepines can be given as shivering raises the body temperature and makes the cooling measures less effective.
Prevention of heat stroke
You can take proactive steps to keep yourself hydrated and cool in hot weather or while performing strenuous activities.
- Decrease or reschedule strenuous activity for cooler parts of the day.
- Wear light and loose-fitting clothing.
- Increase carbohydrate intake and decrease protein intake to decrease endogenous heat production.
- Drink plenty of fluids, even when not thirsty. Avoid alcoholic and caffeinated beverages as they cause dehydration.
- Avoid direct sunlight.
- Take breaks in shaded areas while performing outdoor activities in the sun
- You must be aware of the symptoms of heat stroke and seek medical help immediately
- Protect the vulnerable population, such as older adults, infants and young children, by ensuring they are well hydrated and have access to cool environments.
Conclusion
In a heat stroke, the core body temperature increases to >40°C due to prolonged exposure to intense heat or strenuous activities in hot weather, and the body loses its capacity to regulate temperature. Immediate first aid involves moving the patient to a shaded area, applying ice packs, elevating feet and spraying cool mist and using a fan to accelerate cooling. Further, one must take the necessary precautions during very hot weather and be well hydrated, dress appropriately, take breaks in a shaded area between work (if you work outdoors) and carry enough water when you are with people who are most vulnerable to heat stroke, such as infants, children and older adults. Understanding the symptoms of heat stroke and seeking prompt help is crucial to avoid the complications associated with it, such as organ dysfunction and death.
