The concept of "internal fever" frequently arises when individuals feel hot, experience chills, or sense a general malaise, yet their thermometer displays a normal temperature. According to Dr. Mariana Sobral from CUF Health Centers, this term is often disliked by physicians because it describes a subjective feeling rather than an objective, measurable medical fact. However, the sensation itself indicates that something is occurring within the body, such as the onset of an infection, dehydration, anxiety, hormonal changes, or other forms of general discomfort.
When a person reports feeling feverish internally without a corresponding temperature spike, experts recommend resting for a few minutes in a cool environment before repeating the measurement. Accurate temperature assessment depends on the method used and the individual. Axillary measurement is considered the most comfortable but may be less precise, while oral readings are accurate only if the person has not recently eaten or drunk. Ear and forehead thermometers offer speed but require strict adherence to manufacturer instructions. Rectal measurement remains an option exclusively for infants. Monitoring temperature evolution over time is crucial to detect rising trends even if initial readings do not meet fever criteria.
Physical checks, such as placing a hand on the forehead or kissing someone's lips, are acts of care that neither confirm nor rule out a fever but remain important in a sick context. Diagnostic thresholds differ between adults and children. For adults, a temperature of 38 degrees Celsius or higher is classified as a fever, though a reading of 37.5 degrees accompanied by severe fatigue, prostration, or dehydration may also warrant concern. In children, behavioral assessment and breathing patterns are vital; temperatures from 37.5 degrees can be considered febrile. Specifically, any child under three months with a temperature of 38 degrees requires immediate observation.
Beyond the numerical value, the combination of temperature, age, and general condition determines urgency. Medical emergency services should be contacted immediately if there is difficulty breathing, intense confusion, or convulsions, which can occur at temperatures reaching 40 degrees. While fever is a natural defense mechanism signaling the body is fighting an issue, persistent high temperatures that do not respond to antipyretics or are accompanied by other significant symptoms necessitate professional medical evaluation.
Sources: Observador.