Body temperature is tightly controlled by the hypothalamus, which acts as the body's central thermostat. Heat production mainly occurs through cellular metabolism, muscle contraction, and shivering. Heat loss happens primarily via radiation, conduction, convection, and evaporation through the skin and lungs. When a person is exposed to extreme cold or heat, autonomic responses—such as vasoconstriction, vasodilation, and sweating—activate to maintain the core temperature within a normal range of roughly 36.5°C to 37.5°C.
A fever, clinically known as pyrexia, is a temporary elevation in body temperature driven by the body's immune response. It is not a disease by itself, but rather a vital sign that the body is fighting an abnormality.
The pathological process unfolds in distinct steps:
Fever stems from a wide variety of underlying conditions. Infectious diseases remain the most frequent culprit in clinical practice across Nigeria, including malaria, typhoid fever, respiratory tract infections, and urinary tract infections. Non-infectious triggers also exist and must not be overlooked by the nurse.
Accurate temperature measurement guides diagnosis and treatment monitoring. Nurses use several anatomical routes, each with different normal baseline readings and clinical reliability. Oral and tympanic routes are quick and convenient for cooperative adults. Axillary measurement is common in general ward routines but generally reads slightly lower than core temperature. Rectal measurement remains the gold standard for core body temperature in infants and critical patients.
| Route | Average Variance from Core | Clinical Consideration |
|---|---|---|
| Rectal | Baseline core | Most accurate; contraindicated in neutropenic patients |
| Oral | 0.3°C lower | Affected by recent hot or cold fluid intake |
| Axillary | 0.5°C lower | Easy to perform; sensitive to proper placement technique |
| Tympanic | Varies slightly | Rapid reading; blocked by excessive earwax |
Administering antipyretics aims to promote patient comfort rather than eliminate the fever entirely, since fever is a natural immune response. These drugs work primarily by inhibiting the cyclooxygenase enzymes, which reduces prostaglandin E2 production in the hypothalamus. Common medications include paracetamol and ibuprofen. Nurses must verify weight-based dosing for pediatric patients, monitor for adverse effects like gastrointestinal irritation or hepatotoxicity, and assess the patient's response within one hour of administration.
When managing a patient with a high fever, immediate nursing actions focus on supportive care and safety. Remove excess heavy blankets and clothing to promote natural heat loss. Encourage adequate oral fluid intake to prevent dehydration resulting from increased metabolic rate and diaphoresis. Sponge baths using lukewarm water can be utilized, but avoid ice-cold water or alcohol rubs, as these cause shivering and peripheral vasoconstriction, which paradoxically trap core heat.
Prolonged high fever places significant strain on the body, increasing oxygen demand, heart rate, and respiratory rate. In young children between six months and five years of age, a rapid spike in temperature can trigger febrile seizures. These brief convulsions are generally benign and self-limiting, but they cause immense distress to families. Severe hyperthermia can also lead to dehydration, electrolyte imbalances, and neurological delirium, especially in older adults.
Educating patients and caregivers is essential for safe recovery at home. Instruct family members on how to correctly read a thermometer and administer prescribed weight-based antipyretic dosages. Emphasize the importance of maintaining hydration with clean water, oral rehydration solutions, or soups. Teach caregivers to recognize danger signs that require immediate return to the health facility, such as persistent vomiting, altered consciousness, stiff neck, or breathing difficulties.