Body temperature serves as a significant indicator of health, particularly when the body is fighting off infections like COVID-19. A fever, characterized by an elevated body temperature, is a common symptom across various illnesses. Understanding its thresholds is important for self-monitoring, helping individuals assess their condition and determine when further action may be necessary.
Understanding Fever in COVID-19
A typical body temperature for adults is 97°F to 99°F (36.1°C to 37.2°C), though this varies by age, time of day, and activity. A temperature of 100.4°F (38°C) or higher is considered a fever in adults. While this threshold applies broadly, individual baselines can differ, and fever definitions for children may vary.
Fever occurs as a defense mechanism when the immune system detects an invading pathogen, like a virus or bacteria. The body releases chemicals called pyrogens, which travel to the hypothalamus in the brain, the body’s thermostat. These pyrogens signal the hypothalamus to raise the body’s temperature, creating an environment less favorable for pathogen growth and enhancing immune cell function. This elevated temperature also helps speed up the healing process.
How to Accurately Measure Your Temperature
Accurately measuring body temperature at home involves using a digital thermometer. These thermometers are widely available and can be used orally, temporally (on the forehead), axillary (under the arm), or rectally. Rectal readings are most accurate, especially for infants. Oral readings are accurate for older children and adults, while axillary readings are less accurate.
To take an oral temperature, place the tip of a digital thermometer under the tongue, to one side of the center. Close your lips tightly around the thermometer, avoiding biting down or talking, and breathe normally through your nose. Wait for the thermometer to beep or signal that the reading is complete, which takes less than a minute. For accuracy, wait 20 to 30 minutes after eating or drinking before taking an oral temperature.
For a temporal artery (forehead) thermometer, place the device in the center of the forehead, touching the skin, and gently slide it straight across to the hairline. Some newer models may only require a simple sweep. Ensure the thermometer maintains contact with the skin and read the temperature displayed. Factors like direct sunlight, cold temperatures, or a sweaty forehead can affect accuracy. Clean and dry your forehead beforehand.
When to Seek Medical Attention
While a fever is a sign of the body fighting infection, certain temperatures and symptoms warrant medical attention. For adults, a temperature of 103°F (39.4°C) or higher warrants contacting a healthcare provider. Seek immediate medical consultation if your temperature reaches 104°F (40°C) or higher.
Beyond specific temperature thresholds, other symptoms combined with a fever indicate a need for urgent medical care. These include:
Trouble breathing or shortness of breath
Persistent pain or pressure in the chest
New confusion or inability to wake or stay awake
Changes in skin, lips, or nail bed color (pale, gray, or blue)
Other concerning symptoms with a fever that warrant contacting a healthcare provider include:
A severe headache that does not improve with painkillers
Persistent vomiting
Abdominal pain
Pain when urinating
Seek medical advice if a fever lasts longer than three days despite home treatment or if you feel sicker. Always contact a healthcare provider for guidance instead of attempting to self-diagnose.