Hyperthermia is defined as elevated body temperature due to a break in thermoregulation that arises when a body produces or absorbs more heat than it dissipates. It is a sustained core temperature beyond the normal variance, usually greater than 39 °C (102.2 °F). Such elevations range from mild to extreme; body temperatures above 40 °C (104 °F) can be life-threatening. Hyperthermia differs from fever in that it is characterized by an uncontrolled increase in body temperature that exceeds the body’s ability to lose heat. The setting of the hypothalamic thermoregulatory center is unchanged. In contrast to fever in infections, hyperthermia does not involve pyrogenic molecules.
Common causes of hyperthermia result from the combined effects of activity and salt and water deprivation in a hot environment, such as when athletes perform in scorching weather or when older adults avoid using air conditioning because of expense. Hyperthermia may transpire more quickly in persons who have endocrine-related problems, alcohol consumption, or take diuretics, anticholinergics, or phototoxic agents. Common forms of accidental hyperthermia include heat stroke, heat exhaustion, and heat cramps. Malignant hyperthermia is a rare reaction to common anesthetic agents such as halothane or the paralytic agent succinylcholine. Those who have this reaction, which is potentially fatal, have a genetic predisposition.
Certain individuals, such as the elderly, infants and young children, the obese, outdoor workers, and those with chronic medical conditions, are at increased risk for developing a heat-related illness. A thorough assessment of preoperative patients is necessary for prevention.
Causes of Hyperthermia
Here are some factors that may be related to Hyperthermia:
- Prolonged exposure to hot environment
- Illness or trauma
- Inability to sweat
- Increased metabolic rate
- Vigorous activity
Signs and Symptoms of Hyperthermia
Hyperthermia is characterized by the following signs and symptoms:
- Body temperature above the normal range
- Hot, flushed skin
- Increased heart rate
- Increased respiratory rate
- Loss of appetite
- Malaise or weakness
Goals and Outcomes
The following are the common goals and expected outcomes for Hyperthermia:
- Patient maintains body temperature below 39° C (102.2° F).
- Patient maintains BP and HR within normal limits.
Nursing Assessment and Rationales for Hyperthermia
Assessment is necessary to identify potential problems that may have led to hyperthermia and name any episode during nursing care.
1. Assess for signs of hyperthermia.
Assess for hyperthermia signs and symptoms, including flushed face, weakness, rash, respiratory distress, tachycardia, malaise, headache, and irritability. Monitor for reports of sweating, hot and dry skin, or being too warm.
2. Assess for signs of dehydration as a result of hyperthermia.
Look for signs of dehydration, including thirst, furrowed tongue, dry lips, dry oral membranes, poor skin turgor, decreased urine output, increased concentration of urine, and weak, fast pulse.
3. Monitor the patient’s heart rate and blood pressure.
HR and BP increase as hyperthermia progresses.
4. Identify the triggering factors for hyperthermia and review the client’s history, diagnosis, or procedures.
Understanding the changes in temperature or the cause of hyperthermia will help guide the treatment and nursing interventions.
5. Determine age and weight.
Extremes of age or weight increase the risk of the inability to control body temperature. The elderly are prone to hyperthermia because of the physiologic changes related to aging, the presence of chronic diseases, and the use of polypharmacy (Saltzberg, 2013; Brody, 1994)
6. Accurately measure and document the client’s temperature every hour or as frequently as indicated, or when there is a change in the client’s condition.
Using a consistent temperature measurement method, site, and device will help make accurate treatment decisions and assess trends in temperature. Use two modes of temperature monitoring if necessary. All non-invasive methods to measure body temperature have accuracy and precision variances unique to each type and method compared to core temperature methods. Note that the difference in temperatures between core temperature measurement and other non-invasive methods is considered to be 0.5ºC (Barnason et al., 2012; Sessler et al., 1991; Tayafeh et al., 1998).
7. Monitor fluid intake and urine output. If the patient is unconscious, central venous or pulmonary artery pressure should be measured to monitor fluid status.
Fluid resuscitation may be required to correct dehydration. The significantly dehydrated patient is no longer able to sweat, which is necessary for evaporative cooling.
Nursing Interventions and Rationales for Hyperthermia
The following are the therapeutic nursing interventions for Hyperthermia:
1. Recognize the signs and symptoms of heat exhaustion or heat-related illness.
Heat-related illness occurs when the body’s thermoregulatory system fails. Heat exhaustion is characterized by elevated body core temperature (37ºC to 39.4ºC) associated with orthostatic hypotension, tachycardia, diaphoresis, tachypnea, weakness, syncope, muscle aches, headache, and flushed skin. Exertional hyperthermia, often affecting athletes, can precipitate heat exhaustion. But it can also occur during warm weather or locations with extreme temperatures.
2. Recognize the signs and symptoms of heatstroke.
Heatstroke occurs when the body’s thermoregulation fails and is defined as elevated core body temperature (above 39.4ºC) and central nervous system involvement. Symptoms include delirium, lethargy, red, hot, dry skin, decreased LOC, seizures, coma. Heatstroke is an emergency and, if not treated promptly, can result in death.
3. Loosen or remove excess clothing and covers.
Exposing skin to room air decreases heat and increases evaporative cooling.
4. Provide hypothermia blankets or cooling blankets when necessary.
Use cooling blankets that circulate water when the body temperature is needed to be cooled quickly. Set the temperature regulator to 1ºC below the client’s current temperature to prevent shivering.
5. Provide a tepid bath or sponge bath.
A tepid sponge bath is a non-pharmacological measure to allow evaporative cooling. Do not use alcohol as it can cool the skin rapidly and may cause shivering.
6. Apply ice packs to the patient.
Surface cooling by placing ice packs in the groin area, axillae, neck, and torso is an effective way of cooling the core temperature. When the patient’s core temperature is lowered to 39ºC, it is necessary to remove the ice packs from the patient to avoid overcooling which can result in hypothermia. (O’Connor, 2017).
7. Monitor the skin during the cooling process.
Prolonged exposure to ice can damage the skin. Cover ice packs with a towel and regularly adjust the site of application to mitigate skin damage.
8. Ice water immersion.
Ice water immersion is the most efficient noninvasive technique for lowering core body temperature. This cooling technique can lower body temperature at about 0.15ºC to 0.35ºC per minute (O’Connor, 2017).
9. Infuse intravenous cooled saline as ordered.
Cooled saline is an effective way to decrease core temperature. Cold saline is usually infused over 10-20 minutes. In a study, 18cc/kg of cold saline infusion decreased core temperature by ~1.0ºC in children with acute brain injury who were treated for fever (Fink et al., 2012). Sedation is usually induced during infusion to facilitate effective temperature reduction by preventing shivering.
10. Assist in performing gastric lavage.
Gastric lavage is an invasive cooling technique that can achieve a reduction of about 0.15ºC per minute. Note that gastric lavage may not be suitable for all patients as there is a risk that the infused cold saline may not be retrieved completely and can lead to water intoxication leading to further damage.
11. Assist in performing peritoneal lavage.
Peritoneal lavage is an invasive cooling technique resulting in core temperature reductions of up to 0.08ºC to 0.16ºC per minute. It is a highly effective technique due to the large surface area of the peritoneum.
12. Adjust and monitor environmental factors like room temperature and bed linens as indicated.
Room temperature may be accustomed to near normal body temperature, and blankets and linens may be adjusted as indicated to regulate the patient’s temperature.
13. Modify cooling measures based on the patient’s physical response. Monitor the patient for shivering.
Excessive cooling or cooling too rapidly may cause shivering, which increases metabolic rate and temperature. Shivering should be avoided as it will hinder cooling efforts.
14. Raise the side rails and lower the bed at all times.
Helps ensure the patient’s safety even without the presence of seizure activity.
15. Administer diazepam (Valium) or chlorpromazine (Thorazine) as indicated.
Helps prevent excessive shivering that increases heat production, oxygen consumption, and cardiorespiratory effort. In a study, rapid IV infusion of cold normal saline with 20 mg of intravenous diazepam results in a 0.2ºC to 1.5ºC decrease in core temperature without increasing oxygen consumption during cold saline infusion (Hostler et al., 2009). Administration of diazepam may reduce the shivering threshold without compromising respiratory or cardiovascular function.
16. Provide nutritional support or as indicated.
Food is necessary to meet the increased energy demands and high metabolic rate caused by accompanying hyperthermia. Food must be appealing to the patient because lack of appetite is common with fever.
17. Provide mouth care.
Application of water-soluble lip balm can help with dryness and cracks caused by dehydration.
18. Keep clothing and bed linens dry.
Promotes comfort and helps prevent chilling since diaphoresis occurs during defervescence.
19. Encourage adequate fluid intake.
If the client is alert enough to swallow, provide cool liquids to help lower the body temperature. Additionally, if the patient is dehydrated or diaphoretic, fluid loss contributes to fever.
20. Start intravenous normal saline solutions or as indicated.
Intravenous normal saline solution replenishes fluid losses during shivering chills.
21. Understand that administering antipyretic medications have little use in treating hyperthermia.
Antipyretic medications (e.g., acetaminophen, aspirin, and NSAIDs) have no role in treating heat-related illness or heat stroke. Antipyretics interrupt the change in the hypothalamic set point caused by pyrogens and are not expected to work on a healthy hypothalamus that has been overloaded.
Interventions for malignant hyperthermia
The nurse should have the appropriate medication and equipment available, and be knowledgeable about the protocol to follow during malignant hyperthermia.
1. Perform a thorough history and physical exam to determine if the patient is at risk for malignant hyperthermia.
Trauma, heatstroke, myopathies, emotional stress, strenuous exercise exertion, and neuroleptic malignant syndrome can trigger malignant hyperthermia. Persons who are at risk for malignant hyperthermia include those with a history of muscle cramps or muscle weakness, unexplained temperature elevation, and bulky muscles. Referral to the Malignant Hyperthermia Association of the United States (MHAUS) may be necessary if the patient is at risk for MH. MHAUS can provide information and additional resources for patients with a history of MH.
2. Recognize the signs and symptoms of malignant hyperthermia, initiate treatment as ordered.
Hyperthermia, tachypnea, unexplained rise in end-tidal carbon dioxide that does not respond to ventilation, tachypnea, and sustained skeletal muscle contractions are the manifestations common to persons who suffer from malignant hyperthermia. Mortality from malignant hyperthermia can be as high as 70%, however, prompt recognition of symptoms and rapid treatment can decrease mortality to 10% (Isaak & Stiegler, 2016). Note that MH can develop during an operation or 24 hours after the operation, thus close monitoring of symptoms is necessary.
3. Administer 100% oxygen with a non-rebreather mask.
Hyperventilation with 100% oxygen will help lower end-tidal carbon dioxide and flush out volatile anesthetics. If available, insert activated charcoal filters into the inspiratory and expiratory limbs of the breathing circuit. The filter may become saturated after one hour; therefore, a replacement set of filters should be substituted after each hour of use (Malignant Hyperthermia Association of the United States).
4. Administer dantrolene IV bolus as ordered.
Dantrolene sodium is administered to inhibit muscular pathology and prevent death. It is the only drug effective in the treatment of MH by inhibiting the release of calcium ions from the sarcoplasmic reticulum thereby interfering with muscle contraction (Schneiderbanger et al., 2014). Continuous administration of dantrolene is necessary until the patient responds with a decrease in ETCO2, decreased muscle rigidity, and decreased heart rate.
5. Place ice packs in the groin area, axillary regions, and sides of the neck.
The application of ice packs is a necessary measure to decrease core body temperature.
6. Place urinary catheter.
To monitor urine output per hour and color.
7. Assist in performing iced lavage.
Lavage of the stomach and rectum with cold fluids will dramatically lower body temperature. It is necessary not to lavage the bladder since the fluids can alter the results of urine monitoring.
8. Avoid hypothermia.
Cooling of the patient should be discontinued when the core body temperature reaches 38ºC or below.
9. Administer diuretics (e.g., mannitol, furosemide) as ordered.
During malignant hyperthermia, muscle cells are destroyed and the myoglobin that is released accumulates in the kidneys, obstructing urine flow (myoglobinuria). Diuretics promote and maintain urinary flow and prevent renal damage.
10. Discuss the significance of informing future health care providers of MH risk. Recommend a medical alert bracelet or similar identification.
If the patient is identified to be at risk for MH, alternative anesthetic drugs or methods can be used.
The complete protocol in managing a malignant hyperthermia crisis can be found here.
Patient teaching and home care interventions
Some interventions above can be adapted for home care use. Providing health teachings to the patient and family aids in coping with disease conditions and could help prevent further complications of hyperthermia.
- Determine if the client or significant others have a functioning thermometer at home and know how to use it.
- Educate the patient and family members about the signs and symptoms of hyperthermia and help identify factors related to the occurrence of fever.
- Teach emergency treatment for hyperthermia and hyperpyrexia at home. Immediately move the person to a shady area if they are outdoors. Provide cooling measures such as placing them in a tub of cool water or sponging with cool water.
- Advise clients to monitor symptoms of hyperthermia during times of high outdoor temperatures.
- Preventive measures include minimizing time spent outdoors, use of air conditioning, use of fans, increasing fluid intake, taking frequent rest periods, limiting physical activity, cool baths, and showers.
When going outside during warmer weather, advise clients to wear lightweight clothing, loose-fitting clothes, wear a hat, and minimize sun exposure.
- Stress the need to report persistent elevated temperature, especially among the elderly as they may not present with fever when there is an infection.
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References and Sources
References and sources used for this nursing diagnosis guide for Hyperthermia.
- Barnason, S., Williams, J., Proehl, J., Brim, C., Crowley, M., Leviner, S., … & Papa, A. (2012). Emergency nursing resource: non-invasive temperature measurement in the emergency department. Journal of Emergency Nursing, 38(6), 523-530.
- Brody, G. M. (1994). Hyperthermia and hypothermia in the elderly. Clinics in geriatric medicine, 10(1), 213-229.
- Fink, E. L., Kochanek, P. M., Clark, R. S., & Bell, M. J. (2012). Fever control and application of hypothermia using intravenous cold saline. Pediatric critical care medicine: a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies, 13(1), 80.
- Hostler, D., Northington, W. E., & Callaway, C. W. (2009). High-dose diazepam facilitates core cooling during cold saline infusion in healthy volunteers. Applied Physiology, Nutrition, and Metabolism, 34(4), 582–586. doi:10.1139/h09-011
- Isaak, R. S., & Stiegler, M. P. (2016). Review of crisis resource management (CRM) principles in the setting of intraoperative malignant hyperthermia. Journal of anesthesia, 30(2), 298-306.
- Isaak, R. S. (2016). Malignant hyperthermia: case report. Reactions, 1599, 130-30.
- O’Connor, J. P. (2017). Simple and effective method to lower body core temperatures of hyperthermic patients. The American journal of emergency medicine, 35(6), 881-884.
- Reifel Saltzberg, J. M. (2013). Fever and Signs of Shock. Emergency Medicine Clinics of North America, 31(4), 907–926. doi:10.1016/j.emc.2013.07.009
- Schneiderbanger, D., Johannsen, S., Roewer, N., & Schuster, F. (2014). Management of malignant hyperthermia: diagnosis and treatment. Therapeutics and clinical risk management, 10, 355.
- Sessler, D. I., Lee, K. A., & McGuire, J. (1991). Isoflurane anesthesia and circadian temperature cycles in humans. Anesthesiology, 75(6), 985-989.
- Tayefeh, F., Plattner, O., Sessler, D. I., Ikeda, T., & Marder, D. (1998). Circadian changes in the sweating to-vasoconstriction interthreshold range. Pflügers Archiv: European Journal of Physiology, 435(3), Emergency Nurses Association