INTRODUCTION:

Children differ from adults with respect to their anatomical and physiologic response to heat stress. Normally children have a body temperature 37⁰C or 98.6⁰F and when exposed to sun the temperature may exceed more than 40⁰C. These differences translate into a potentially greater risk for severe heat illness, especially in children and adolescents.

Heat illness occurs along a spectrum of disease from minor syndromes (e.g., malaria, heat cramps) to life-threatening processes, such as heat stroke. A number of heat related illnesses exist such as: heat edema, heat rashes, heat cramps, heat exhaustion, and heat stroke which may be fatal if not treated promptly and properly.

Definition:
Heat stroke is defined as a core temperature ≥40⁰C (104⁰F) accompanied by central nervous system dysfunction in patients with environmental heat exposure.

Heat stroke is characterized by extreme elevation of body temperature (hyperthermia) and associated central nervous system dysfunction, organ dysfunction and can cause permanent brain damage.

Classification:

1. Exertional heat stroke: Typically occurs in younger athletic individuals who exercise vigorously in the heat until the body's normal thermoregulatory mechanisms are overwhelmed.

2. Classical or non-exertional heat stroke: more commonly occurs in older individuals or in those with underlying illnesses who are exposed to extreme environmental temperatures and/or humidity.

Risk factors:

Anyone can develop heatstroke, but several factors leads to increased risk such as:

1. Young or old age: In the very young, the central nervous system is not fully developed and in adults over 65, the central nervous system begins to deteriorate, which makes the body less able to cope with changes in body temperature. Both age groups usually have difficulty remaining hydrated, which also increases risk.

2. Genetic response to heat stress: The way the body responds to heat is partly determined by inherited traits. Genes may play a vital role in determining how our body will respond in extremely hot conditions.

3. Situations: Common examples of situations that can lead to heatstroke include military training in hot weather and participation in school sports such as football etc.

4. Sudden exposure to hot weather: People not used to high temperatures, they may be more susceptible to heat-related illness.

5. Lack of air conditioning: Fans may make feel better, but in sustained hot weather, air conditioning is the most effective way to cool down and lower humidity.

6. Certain medications: Some medications place you at a greater risk of heatstroke and other heat-related conditions because they affect the body's ability to stay hydrated and respond to heat. E.g: vasoconstrictors, illegal stimulants such as amphetamines and cocaine.

7. Certain health conditions: Certain chronic illness such as heart and lung disease, overweight, lack of physical fitness.

Pictures to add in prevention/ Health Education:

Signs and symptoms:

Signs:

Temperature: High body temperature, exceeds 41°C.

Pulse: increased pulse rate i.e.,> 86 per minute.

Blood pressure: decreased blood pressure, hypotension i.e., 110/60 mm of Hg.

Heatstroke symptoms include:

High body temperature.

Lack of sweating: In heatstroke brought on by hot weather, the skin will feel hot and dry to touch. However, in heatstroke brought on by strenuous exercise, skin may feel moist.

Nausea and vomiting: May feel sick to the stomach or vomit.

Flushed skin: Skin may turn red as the body temperature increases.

Rapid breathing: Breathing may become rapid and shallow.

Racing pulse rate: Pulse may significantly increase because heat stress places a tremendous burden on the heart for help to body cool.

Headache: May experience a throbbing headache.

Confusion: May have seizures, hallucinate, or have difficulty speaking or understanding what others are saying.

Unconsciousness: May pass out or fall into a state of deep unconsciousness (coma).

Muscle cramps or weakness: Muscles may feel tender or cramped in the early stages of heatstroke, but may later go rigid or limp and may results in rhabdomyolosis.

Investigations:

History collection and physical examination is been collected by physician and it is as follows:

1. History:

The individual may complain of:

· Headache

· Excessive thirst

· Weakness

· Loss of appetite

· Nausea

· Vomiting

2. Physical exam:

a. The critical feature of heat stroke is neurological dysfunction, which may be manifested by:

· Confusion

· Problems with walking

· Lack of coordination of movements, seizures

· Dilated pupil

· Coma

b. Vital signs will reveal:

· Temperature 104° F to 106° F (40° C to 41.1° C)

· Increased pulse rate (tachycardia)

· Rapid, shallow respirations

· Sweating may or may not be present

· Urine output may be scant or absent (<400 ml/24 hrs)

3. Laboratory Tests

· Blood test: To check for low blood sodium or potassium in the blood to check any damage to central nervous system.

· Urine test: To check the color of the urine, because it's usually becomes dark and scanty and to rule out myoglobinuria as in rhabdomyolosis.

· Muscle function test to rule out rhabdomyolosis.

· X-rays and other imaging tests (CT scan and MRI): To check the damage of internal organs for damage to internal organs.

Treatment:

1. Home remedies and modified lifestyles/healthy habits

· Get to a shady or air-conditioned place: Remaining in the heat will worsen the body condition.

· Cool off with damp sheets and a fan: cool the person by covering him or her with damp sheets or by spraying with cool water. Direct air on to the person with a fan.

· Take a cool shower or bath: If outdoors, by soaking in a cool pond or stream also can help bring the temperature down.

· Rehydrate: sports drinks will replenish both water and salt.

· Don't drink beverages with alcohol to rehydrate: These drinks may interfere with the body's ability to control the temperature.

2. First aid:

· Avoid exposure to heat.

· Move to a cool place and rest.

· Call local emergency medical service. Heat stroke is a life-threatening medical emergency and needs to be treated by a physician.

· Remove excess clothing and drench skin with cool water.

· Place ice bags on the armpits and groin aspects.

· Offer cool fluids if alert and able to drink.

3. Treatment in Hospital:

Lower the elevated body temperature by using following measures:

· Take the body in the cool and shady aspect and apply cool or ice water to lower the body temperature.

· Use evaporation cooling techniques, cool water is misted on the skin while warm air fanned over the body causes the water to evaporate, thus cooling the skin.

· Wrap the individual in special cooling blanket and apply ice packs to the groin, neck, back and armpits to lower the temperature.

· If shivering, administer benzodiazepines drugs, which is a muscle relaxant to control the convulsion.

· If benzodiazepines is not effective administer Phenobarbital drug.

· Administer I. V. Fluids to treat hypotension

· Infusing large amounts of intravenous fluids (may require as much as 10 L), alkalinization of urine, and mannitol infusion to treat rhabdomyolysis.

Complications:

· Heatstroke is a multisystem disorder that potentially can affect almost every organ system.

· Hot and dry skin.

· Blue lips and nails.

· Low blood pressure.

· Central Nervous System damage like convulsions, etc.

· Rhabdomyolysis (It is the breakdown of muscle fibers that leads to the release of muscle fiber contents (myoglobin) into the bloodstream which is harmful to the kidney and causes kidney damage).

· ARF (Acute renal failure) especially Exertional Heat Stroke.

· Acute liver failure due to hepatic necrosis and cholestasis generally occurs in the first 48 hours.

· ARDS (Acute Respiratory Distress Syndrome)

Prevention:

Some general guidelines to help protect the adolescent from heat-related illnesses include the following:

· Drink plenty of fluids during vigorous or outdoor activities (including sunbathing), especially on hot days which helps in sweating, maintain normal body temperature and prevent dehydration.

· Advice to drink 7-8 litre of fluid/day to prevent heat stroke.

· Make sure that adolescent dresses in light coloured, lightweight, tightly-woven, loose-fitting cotton clothing on hot days because it reflects sun ray and keep the body cool.

· Schedule vigorous activity and sports for cooler times of the day. Take rest periods in shady or cool aspects.

· Makes sure that adolescent is protected from the sun and wears a hat and sunglasses, and uses an umbrella. Use a sunscreen that is at least SPF (sun protection factor) 15.

· Increase time spent outdoors gradually to get the adolescent's body used to the heat.

· Teach adolescents to take frequent drink breaks and "wet down" or mist them with a spray bottle to avoid becoming overheated.

· Try to spend as much time indoors as possible on very hot and humid days.

· Teach adolescent to warm-up and cool-down before and after exercising.

· Advice to use fan and air conditioners to keep cool in hot indoors.

· If adolescent has a medical condition or taking medication, consult the physician for further advice for preventing heat-related illnesses.

Health education:

1. Media, public education, public health programs, and athlete safety programs can play a pivotal role in increasing the public's awareness of the dangers of heat during heat waves and advising the public on methods of remaining cool.

2. Drinking fluids on schedule (and not based only on thirst), frequent cooling breaks, and frequent visits to air-conditioned places are very important because even short stays in an air-conditioned environment may drastically reduce the incidence of heatstroke.

3. Recognise the host risk factors and modify the behaviour (eg, limiting alcohol and drug intake and the use of medications and drugs that interfere with heat dissipation) and physical activity also will prevent heatstroke.

4. Educate to have nutritious diet and contraindicate the fluids such as alcohol and beverages during hot weather.

CONCLUSION:

In a hot environment, the body rids itself of excess heat through increasing blood flow to the skin, sweating and breathing out warmed air. These mechanisms can sometimes be overwhelmed, however, leading to heat-related symptoms, which, if left untreated, can lead to sunstroke those can be treated by lowering the body temperature by using cooling techniques. It can also prevented by advising to drink plenty of fluids to prevent dehydration and restricting the vigorous activity during hot weather.

BIBLIOGRAPHY:

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3. Bouchama A, Knowche L P. Heatstroke: The Merck Manuals: The Merck Manual for Healthcare Professionals; Aug. 4, 2011; P-276.

4. Becker JA. Heat-related illness: American Family Physician; 2011; 83:1325.

5. Marom T, Lavon H .Hyperthermia: Too hot for the health. National journal for paediatric medicine; May 27, 2011; P-365.

6. Joyce M Black, Jane Hokanson Hawks; “A text book of medical surgical nursing”; 8^th edition; Volume-2; Page no. 2212.

7. Joytol, Arthur. “A Text book of medical physiology”; 5^th edition: Philadelphia: W.B. Saunders publication; 2006; p-116.

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Received on 18.02.2014 Modified on 12.03.2014

Int. J. Adv. Nur. Management 2(1):Jan. - Mar., 2014; Page 34-37

Summayya Abareen