What body temperature is considered a fever?
Fever is the body's response to infection and other conditions.
A fever is defined as a body temperature that is higher than normal. The normal body temperature, however, varies slightly among different individuals. The average normal body temperature is 98.6°F (or 37°C).
- For adults, a fever is when the body temperature is higher than 100.4°F.
- For children, a fever is when their body temperature is more than 100.4°F (measured rectally), 99.5°F (measured orally) or 99°F (measured under the arm).
Having a fever means the body’s immune system is fighting against infections. This is a good sign in most cases. If the fever is between 100.4 and 102°F, it is considered a low-grade fever. A low-grade fever may not require treatment in most cases. If the body temperature goes beyond 102°F, treatment is essential.
When should one visit a doctor for the treatment of a fever?
A fever between 100.4 and 102°F is considered a low-grade fever. A low-grade fever may not require treatment in most cases. Treatment for a low-grade fever is needed if the fever occurs in very young infants (less than three months of age) or if it’s accompanied by serious symptoms such as confusion or inability to eat or drink without vomiting or stomach upset.
One must visit a doctor for fever management if
- A fever is accompanied by neck stiffness, confusion or irritability.
- A fever remains above 103°F (39.5°C) for more than two hours after home treatment.
- A fever lasts longer than two days.
- A fever is accompanied by a rash.
- There is photophobia (intolerance to light).
- There are signs of dehydration such as less amount of urine, sunken eyes and absence of tears.
- The person gets seizures or any abnormal movements or becomes unresponsive.
If a fever rises above 105°F (or 40.5°C) and does not come down with treatment, urgent medical help must be sought because it is a life-threatening emergency.
What causes a fever?
The body has an internal thermostat that regulates body temperature, usually around 98.6°F, despite the changing temperature in the surroundings. Any infection or stress can “reset” the thermostat causing a fever. A fever does not mean a disease. It is rather a sign that the immune system is actively trying to fight an illness or infection. When someone has a fever, the body temperature increases, making it harder for bacteria or viruses to survive.
Some of the common causes of a fever are as follows
- Common cold
- Ear or throat infections
- Urinary tract infections (UTI)
- Mononucleosis, which is a contagious illness that is most commonly caused by Epstein-Barr virus (EBV) and certain other infections. It is also called “the kissing disease” because it spreads easily through body fluids such as saliva.
- Medicines such as certain antibiotics, blood pressure medicines and anti-seizure medications
- Heat stroke
- Autoimmune diseases such as lupus
- Certain childhood immunizations
- Menstrual periods
- Heavy clothing
- Rigorous exercise
- Dehydration, especially in newborns
What is the best way to measure a fever?
The best way to measure a fever or body temperature is by using a thermometer. It can be inserted into the mouth (orally), into the rectum (rectally) or under the arm (axillary). A fever can also be recorded by using a special instrument, commonly available in stores, that is inserted in the ear and records the eardrum temperature.