Hyperthermia is an increase in body temperature that occurs especially after sunburns and heatwaves. However, it can also be a manifestation of malignant hyperthermia, a pharmacogenetic complication that can be associated with the use of certain medications.
What is hyperthermia?
Hyperthermia is an increase in body temperature above the normal range, which is usually between 97.7 °F and 99.5°F. It is often characterized by a body temperature above 104°F.
Hyperthermia is the result of heat accumulation of endogenous or exogenous origin, i.e., heat generated internally or externally to the body.
Under normal circumstances, heat production (thermogenesis) is balanced by heat loss (thermolysis) to maintain thermal equilibrium. This balance is regulated by the thermoregulatory center in the brain.
NB: A distinction must be made between hyperthermia and fever. Although both phenomena are characterized by an increase in body temperature, they do not have the same origin. Hyperthermia is caused by a buildup of heat and is an abnormal phenomenon. Fever, on the other hand, is caused by a shift in the thermal equilibrium point and is a defense mechanism of the body.
What Causes hyperthermia?
Hyperthermia can have several causes, including:
- Exposure to strong sunlight commonly referred to as sunburn
- Excessive heat in the environment could cause a heat stroke, which occurs especially during heatwaves.
- Saunas and steam baths.
- Intense physical activity (strenuous heat stroke).
- The effects of certain drugs on the body, especially amphetamines and cocaine.
- The use of certain medications, such as muscle relaxants and anesthetics.
*Malignant hyperthermia is a complication of taking certain medications or a complication of anesthesia.
Diagnosis of hyperthermia
The diagnosis of hyperthermia is based primarily on clinical examination. This includes distinguishing hyperthermia from an episode of high fever.
Some further investigations may be performed to confirm and/or investigate the cause of hyperthermia. These may include blood, urine, or muscle tissue tests.
People affected by hyperthermia
Hyperthermia can affect a large number of people if not properly prevented. However, certain populations have been found to be at higher risk:
- Elderly and/or frail people who are particularly susceptible to heatwaves or prolonged sun exposure.
- Long-distance athletes, such as marathon runners.
- Anyone who engages in prolonged physical exertion in hot weather and/or direct sunlight.
Malignant hyperthermia may occur in patients who have been under anesthesia or treatment with muscle relaxants. The prevalence would be approximately 1 in 20,000 patients. In addition, there is an inherited genetic predisposition.
Risk factors for hyperthermia
Several factors may increase the risk of hyperthermia:
- Neurological pathologies
- Taking certain medications
- Lack of hydration and dehydration
- Cardiovascular diseases
- Social isolation, especially during heatwaves
- Alcohol consumption
- Sleep deprivation
- Illegal drugs
Symptoms of hyperthermia:
- Increased body temperature: hyperthermia is characterized by an increase in body temperature. It is usually above 104°F.
- Neurological disorders: The increase in body temperature is often accompanied by neurological disorders such as impaired consciousness, confusion, delirium, or convulsions. This is referred to as hyperthermic convulsion.
- In the most severe cases, hyperthermia can lead to a coma.
- Possible tachycardia: Tachycardia, an increased heart rate, is also a common symptom of hyperthermia.
- Consequences of malignant hyperthermia: In addition to the above symptoms, malignant hyperthermia may be accompanied by other clinical manifestations such as muscle stiffness. Further investigation may also reveal increased oxygen consumption, increased carbon dioxide production, acidosis (abnormal decrease in blood pH), and rhabdomyolysis (rapid breakdown of skeletal muscle cells).
Treatment of hyperthermia
Hyperthermia requires urgent medical attention as it can have serious consequences for the body.
The first step in treating hyperthermia is to cool the body down. This can be done by removing several layers of clothing, moistening the skin, applying ice, using air conditioning, etc.
In case of hyperthermia, other measures are usually taken. Rehydration of the body is done in case of sunburn or heatwave. Medical treatment may also be considered to treat some of the symptoms of hyperthermia.
Prevention of hyperthermia
Hyperthermia can be prevented by limiting avoidable risk factors. For example, it is recommended to:
- Limit exposure to heat
- Drink enough water
- Do not neglect hydration before, during, and after physical activity.
- Do not overexert yourself when exercising.
If your symptoms are severe, it is recommended that you contact a health care professional ASAP.