Heatstroke

Heatstroke is a life-threatening condition that occurs when your body temperature reaches above 104 F (40 C). Human body has limited capabilities to sustain extreme high temperature. Exposure to heat can cause the damage to our brain and other essential organs of body. Heatstroke can occur not only due to exposure to high environmental temperatures but also due to strenuous physical activity or by other conditions that raise your body temperature. Whatever the cause, you'll need immediate medical attention to prevent brain damage, organ failure or death. It is a common problem in the tropical countries, and with ever-increasing global warming heat related illness are seen more frequently even in temperate climate. In India,

Northern and Western areas experiences extreme high temperatures during summers, which results in high incidence of heat stroke. Heat cramps and heat exhaustion are milder manifestations of heat-related health problems but can escalate to more serious problem of heatstroke.

Symptoms

Author Dr. Yashpal Singh (CMC)

Severe and prolonged heat exposure can leads to various symptoms’

High body temperature 104 F (40 C) or higher is the main sign of heatstroke.
A lack of sweating. In heatstroke brought on by hot weather, your skin will feel hot and dry to the touch. However, in heatstroke brought on by strenuous exercise, your skin usually feels moist.
Flushed skin. Your skin may turn red as your body temperature increases.
Rapid breathing. Your breathing may become rapid and shallow.
Racing heart rate and strong pulse (tachycardia). Your pulse may significantly increase because heat stress places a tremendous burden on your heart to help cool your body.
Neurological symptoms. Headache is one of the commonest and early neurological symptom of heatstroke. You may have more serious manifestations like seizures, loss of consciousness, and hallucinations.
Muscle cramps or weakness. Your muscles may feel tender or cramped in the early stages of heatstroke, but may later go rigid or limp.

Causes

Heatstroke is the escalation of two less serious heat-related conditions. Recognition and early management of heat cramps and heat exhaustion prevents development of heatstroke:

Heat cramps. Initial exposure to extreme temperatures or physical exertion or both can leads to signs and symptoms of heat cramps usually include profuse sweating, fatigue, thirst and muscle cramps, usually in the stomach, arms or legs. This condition is common in hot and humid weather in our country or with moderate to heavy physical activity. You can usually treat heat cramps by drinking fluids containing electrolytes (Shikanji), resting and getting to a cool spot, like a shaded or air-conditioned area.

Heat exhaustion. Heat exhaustion is more severe condition occurs when you don't act on the signs and symptoms of heat cramps. Signs and symptoms of heat exhaustion include a headache, dizziness or lightheadedness, nausea, skin that feels cool and moist, and muscle cramps. Often with heat exhaustion, you can treat the condition yourself by following the same measures used to treat heat cramps, such as drinking cool nonalcoholic beverages, getting into an air-conditioned area or taking a cool shower. If your symptoms persist, seek medical attention immediately.

The cause of your heatstroke depends on the activities you do that bring on your condition. Heatstroke can occur in these ways:

Environmental conditions. Nonexertional heatstroke is typical in hot weather we are experiencing in this summer. In coming months when weather will be more humid and hot, the incidence of heatstroke will be high. The extreme environment temperatures cause your body temperature to increase. You may be doing some light or moderate activity, but activity is not the primary cause of your heatstroke.
Strenuous activity. Exertional heatstroke, caused by strenuous activity that increases your body temperature. You can have exertional heatstroke even if you're accustomed to working or exercising in very hot temperatures, though heatstroke is more likely to occur if you're not accustomed to high temperatures.

Dehydration, drinking alcohol can further expose you to develop heatstroke.

Who are at risk

Anyone can have heatstroke, but several factors may place you at greater risk:

Young or old age. Heat stroke often occurs in people who are unable to modify their environments: infants, the elderly and bed-ridden people The coping mechanism of body to sustain in stressful condition is weak in children and elderly. Both age groups usually have difficulty remaining hydrated as well, also increasing risk.
Genetic response to heat stress.. Researchers believe that your genes may play a vital role in determining how your body will respond in extremely hot conditions.
Hot-weather intolerance. If you're not used to high temperatures or high humidity, you may be more susceptible to heat-related illness if you're exposed to a sudden increase in temperature, as might happen with a heat wave that occurs during late spring. Limit your physical activity for at least several days until you've acclimated to the higher temperatures and humidity. However, you may still have an increased risk of heatstroke until you've experienced several weeks of higher temperatures.
Outdoor activities. If you have to work outside, or you participate in school or professional sports that require you to practice outdoors in the summer, you have a higher risk of heatstroke.
Certain medications. Some medications are likely to increase risk of heatstroke and other heat-related conditions because they affect your body's ability to stay hydrated and respond to heat. Be especially careful in hot weather if you take medications that narrow your blood vessels (vasoconstrictors), regulate your blood pressure by blocking adrenaline (beta blockers), rid your body of sodium and water (diuretics), or reduce psychiatric symptoms (antidepressants or antipsychotics). Additionally, stimulants, such as amphetamines and cocaine, increase your body's heat production, making you more vulnerable to heatstroke.

Complications

A possible complication of heatstroke is shock, which is a condition caused by severe decrease in of blood flow to body organs. Signs of shock include a very low blood pressure, blue lips and nails, and cool, clammy skin. Shock can lead to permanent damage of vital organs if it's not treated quickly and adequately.

Treatments

Cooling your body to a normal temperature as quickly as possible is the aim of treatment, in order to prevent or reduce damage to your brain and vital organs. To do this, your doctor may:

Immerse you in cold water. Your doctor may immerse your body in a bath of cold water or ice water to quickly lower your temperature.
Use evaporation cooling techniques. Your doctor mists cool water on your skin and fans warm air over your body to evaporate the water on your skin.
Pack you with ice and cooling blankets. Another method is to wrap you in a special cooling blanket and pack your groin, neck, back and armpits with ice packs to lower your temperature.
Stop your shivering. If any treatments to lower your body temperature make you shiver, your doctor may give you a muscle relaxant, such as a benzodiazepine. Shivering increases your body temperature, making treatment less effective.

Prehospital remedies

Heatstroke is a medical emergency. You shouldn’t try to treat it at home.

However, if you notice signs of other heat-related illness before any noticeable signs or symptoms of heatstroke appear, you can take action to lower your body temperature and prevent your condition from progressing to heatstroke. In a lesser heat emergency, such as heat cramps or heat exhaustion, you can take the following steps for yourself and others:

Get to a shady or air-conditioned place. Remaining in the heat will worsen your condition. If you don't have air conditioning at home, go someplace that is air-conditioned, such as the mall, movie theatre or public library.
Cool off with damp sheets and a fan. If you're with someone who's experiencing heat-related symptoms, cool the person by covering him or her with damp sheets or by spraying with cool water. Direct air onto the person with a fan.
Take a cool shower or bath. If you're outdoors and nowhere near shelter, soaking in a cool pond or stream can also help bring your temperature down.
Rehydration. Keep in mind that the symptoms of heat-related illnesses are caused not only when you become dehydrated, but also when you lose salt through sweating. Some sports drinks will replenish both water and salt. The amount you'll need to drink to rehydrate varies from person to person, so sip slowly and call your doctor if you're concerned. And, if you're on a low-sodium diet, be sure to check with your doctor before consuming drinks with a high salt content.
Don't drink beverages with alcohol or caffeine for fluid replacement. These drinks may interfere with your body's ability to control your temperature.

Prevention of heat related illness

Heatstroke is serious but easily preventable condition. We can prevent heat-related illness by practicing simple precautions during hot weather condition

Wear loose fitting, lightweight clothing. Wearing excess clothing or clothing that fits tightly won't allow your body to cool properly by allowing your sweat to evaporate.
Seek a cooler environment. A good way to start cooling off is to get to a cooler environment, like an air-conditioned building or a shady spot.
Drink plenty of fluids. Staying hydrated will help your body sweat and maintain a normal body temperature.
Take extra precautions with certain medications. Several medications can affect your body's ability to stay hydrated.People who are taking many types of blood pressure, allergy, or depression medication may also be particularly at risk and should avoid hot environments
Avoid being inside a hot car. When parked in the sun, the temperature in your car can rise 20 F (more than 11 C) in just 10 minutes. Never leave children or anyone else in a parked car in hot weather for any period of time.
Avoid strenuous activity in the heat. It's best not to exercise or do any strenuous activity in hot weather, but if you must, follow the same precautions and rest frequently in a cool spot. Try to schedule exercise or physical labor for cooler parts of the day, such as early morning or evening. Taking breaks and replenishing your fluids during that time will help your body regulate your temperature. People like coaches, trainers, and lifeguards and lifeguards should be trained to specifically recognize signs of heat illness and what preventive measures to take.

· When to see a doctor
If you think you have heat cramps or the beginning signs and symptoms of heat exhaustion, first try to cool yourself and replenish your water and salt levels. If your condition has progressed past heat cramps and heat exhaustion and you feel any of the symptoms of heatstroke, seek immediate medical attention.

Heat related illnesses are important medical emergencies which are often misdiagnosed and mismanaged. The incidence of heat stroke is increasing with increased global warming. Greater awareness among general public and special groups who are exposed to high temperature regarding heat related illness will

Help in recognizing and treating these disorders at an early stage. Heat stroke is a preventable fatal condition and high index of clinical suspicion in appropriate setting can save the patient from more serious outcomes. Public education on heat illnesses is need of hour. Simple measures like restricted use of alcohol, enforced rests and increased and regular fluid intake, availability of cooling facilities for people working in hot areas will help in decreasing the effect of high temperature.

Dr. Yashpal Singh

Professor

Deptt of Neurology

Christian Medical College and Hospital

Ludhiana

9814814044