Heat stroke is defined as a core temperature of ≥40°C with central nervous system dysfunction due to environmental heat exposure, categorized into classic and exertional types. The document outlines the clinical features, predisposing factors, management strategies including cooling methods, and complications associated with heat stroke. It emphasizes the importance of timely treatment and preventive measures to reduce the risk of heat-related illness.

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2. Heat Stroke
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PREPARED BY:
RN Arpana Bhusal
BNS

3. DEFINITION
• A core temperature ≥40°C
accompanied by CNS dysfunction
in patients with environmental heat
exposure. This condition represents
a failure of the body's ability to
maintain thermoregulatory
homeostasis.
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4. CLASSIFICATION
• Classic (non-exertional) heat stroke :
more common in younger children who
are unable to escape from hot
environments and those with underlying
chronic medical conditions that impair
thermoregulation.
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5. CONT…
• Exertional heat stroke : generally
occurs in healthy individuals who
engage in heavy exercise during
periods of high temperature and
humidity. Typical patients are
athletes and military recruits in basic
training
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6. PREDISPOSING FACTORS
• Increased heat production e.g. hyperthyroidism, exercise, sepsis
• Impaired heat loss – impaired sweating e.g. drugs ,abnormal sweat glands
• Impaired delivery of blood to peripheral circulation cardiovascular disease,
hypokalemia, dehydration
• Others :
 elderly,
obesity,
fatigue, DM 9/14/2022 6

7. CLINICAL FEATURES
• The diagnostic criteria are elevated core temperature (≥40°C) and
(CNS) abnormalities following environmental heat exposure.
• 3 cardinal signs are
CNS dysfunction
Hyperpyrexia
Hot dry skin, pink or red depending on circulatory state
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8. CONT…
Children commonly present with more significant neurologic symptoms
such as –
seizures
 delirium
 hallucinations
 ataxia
coma
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9. OTHER CLINICAL MANIFESTATIONS
• Tachycardia
• Tachypnea
• The skin may be flushed and warm or diaphoretic.
• Vomiting and diarrhea are also common.
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10. CONT…
Those patients with coagulopathy may demonstrate
 purpura
 hemoptysis
 hematemesis
melena
 hematochezia
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11. NEUROLOGIC ABNORMALITIES:
• Permanent neurologic damage is more commonly seen in
patients with core temperatures >42ºC (107.6ºF) and consist of
 spasticity,
ataxia,
 dysarthria,
 poor coordination,
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12. CONT…
impaired memory, and
 behavioral changes.
• Patients recovering from rapidly treated exertional or classic heat
stroke with core body temperatures below this level may manifest
some of these neurologic findings but typically recover full.
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14. PRE-HOSPITAL CARE
• Cooling might have occurred prior to the arrival of the hospital.
• Removal from the source of heat stress and rapid initiation of
cooling, as the risk of morbidity and mortality for patients with heat-
related illness is associated with the duration of hyperthermia.
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15. CONT…
• Patients with heat stroke should be treated with either ice water
immersion or evaporative external cooling in the field.
• Pre-hospital cooling measure should be initiated prior to or
simultaneously with activation of emergency medical services.
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17. CONT…
• Evaporative cooling may be accomplished in the field by spraying
patients with water or saline and fanning these patients, either
manually or with ambulance fans or air conditioners. Application of
ice packs to the neck, axillae, and groin.
• The institution of pre-hospital cooling should not delay timely
transportation to definitive care
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18. Evaporative External Cooling
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19. HOSPITAL MANAGEMENT
• Stabilization: In addition to the careful assessment and support of
airway, breathing, and circulation, the clinician should anticipate and
aggressively manage hyperthermia, dehydration, rhabdomyolysis,
DIC, high output cardiac insufficiency, renal and hepatic failure.
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20. CONT…
• Altered mental status typically resolves once oxygenation, adequate
tissue perfusion, and normothermia are achieved.
• Seizures should be treated with benzodiazepines (lorazepam
0.1mg/kg,IV)
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21. RAPID COOLING
• Evaporative cooling is achieved by spraying patients with tepid water (to
minimize shivering) while fanning with high-flow fans to maximize air
circulation.
• Cooling rates approaching 0.15ºC per minute have been achieved in
adults.
• Alternatively, the patient may be placed on a cooling blanket. If tolerated,
selective application of ice packs to the neck, axillae, and groin during
evaporative cooling may be of additional benefit.
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22. COOLING BLANKETS 9/14/2022 22

23. CONT…
Cold water immersion:
• Cold water immersion is another adjunctive cooling modality when
evaporative cooling with or without selective ice application is not
possible.
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24. CONT…
Internal Cooling
• The most effective method of lowering the core body temperature
quickly is the use of cardiopulmonary bypass; however, this highly
specialized intervention is not rapidly available at most institutions.
Newer, less invasive devices such as intravascular cooling catheters
have been utilized to rapidly induce therapeutic hypothermia
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25. Intravascular Cooling Catheters
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26. CONT…
• Gastric, rectal, and/or bladder lavage with cold isotonic fluids (e.g.,
normal saline that has been iced) have been proposed as additional
means of invasive cooling.
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27. PHARMACOLOGIC THERAPY
• Medications have a limited role in the management of heat stroke.
However, pharmacologic measures taken to prevent shivering.
• Patients with heat stroke should receive benzodiazepines (e.g.,
midazolam 0.05 to 0.1 mg/kg iv ) to prevent shivering during cooling
measures.
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28. CONT…
• Although antipsychotic agents (chlorpromazine) have been used in
adults to prevent shivering, it may exacerbate hypotension in heat
stroke victims.
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29. COMPLICATIONS
• After stabilization and rapid cooling, the victim with heat stroke
remains at high risk for multiple organ failure, metabolic
abnormalities, and disorders of coagulation.
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30. CONT…
 Rhabdomyolysis with hyperkalemia
 hypocalcemia and hyperphosphatemia
 DIC
Acute kidney injury
Hyponatremic dehydration
 Cardiogenic shock with low systemic vascular resistance
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31. CONT…
• Cardiogenic and noncardiogenic pulmonary (ARDS)
• Liver failure : Treatment is supportive. Rarely, liver transplantation
has been necessary in teenagers with heat stroke-associated liver
failure.
• Cerebral edema
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32. PREVENTING HEAT-RELATED ILLNESS
• Dress for the heat : Wear lightweight, light-colored clothing. It is also
a good idea to wear hats or to use an umbrella.
• Drink water : Carry water or juice and drink continuously even if we
do not feel thirsty. Avoid alcohol and caffeine, which dehydrate the
body.
• Avoid foods that are high in protein, which increase metabolic heat.
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33. CONT…
• Stay indoors when possible.
• Take regular breaks when engaged in physical activity on warm days.
• Take time out to find a cool place.
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34. POINT TO BE REMEMBER..
• Children with elevated body temperature and CNS abnormalities
should be treated as victims of heat stroke.
• Rectal temperature is the most commonly obtained core temperature
measurement.
• Morbidity or mortality are directly related to duration and degree of
hyperthermia.
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35. CONT…
• The institution of prehospital cooling should not delay timely
transportation to definitive care.
• The most effective method of lowering the core body temperature
quickly is the use of cardiopulmonary bypass.
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37. REFERENCES:
• 2021. Slideshare. Heatstroke. https://www.slideshare.net/drasimrana/heat-stroke-
37983872 @2021/07/07 at 2pm
• July 16. 2019. Mayoclinic. Heatstroke. https://www.mayoclinic.org/diseases-
conditions/heat-stroke/symptoms-causes/syc-20353581 @2021/ 07/07 at 3pm
• 2020. WebMD. Heatstroke. https://www.webmd.com/a-to-z-guides/heat-stroke-
symptoms-and-treatment @2021/07/08 at 11am
• March 8. 2019. Vetfolio. Heatstroke: Thermoregulation, Pathophysiology, and
Predisposing Factors. https://www.vetfolio.com/learn/article/heatstroke-
thermoregulation-pathophysiology-and-predisposing-factors. @2021/07/08 at 10
pm 9/14/2022 37

38. Thank You 9/14/2022 38