A healthy person's body temperature fluctuates between 97°F (36.1°C) and 100°F (37.8°C), with the average being 98.6°F (37°C). An elevation in body temperature above 100°F (37.8°C) is termed as fever.

Fever is a symptom and not a disease and can be caused by numerous reasons, such as bacterial or viral infections or even by excessive exposure to the sun. In most cases, fever needs symptomatic treatment in form of fever reducing medication, plenty of fluids, and rest.

What do you need to know about symptoms or signs?

You will experience the following signs and symptoms during a fever:

Temperature higher than 100.4 F (38 ^oC) in adults and children
Shivering, chills
Muscle and joint ache
Headache
Intermittent sweats
Rapid heart rate or palpitations
Dizziness or lightheadedness
Weakness

What are the causes of fever?

Fever only requires symptomatic treatment in the following cases:

Viral fever: Viral infections are associated with rise in body temperature, a condition known as viral fever. Though all viral infections show generalised symptoms, different viruses target specific organs. Fever, along with headache, body ache and skin rash are the common characteristics of most viral fevers.

Viral fever only requires symptomatic treatment, though specific infection may persist as the virus continues to multiply. Some viral infections may be extremely contagious, but most are not dangerous and are self-limiting. Viral fever is treated symptomatically with antipyretic and analgesic drugs. Most viral fevers recover within a week, although you may experience fatigue for couple of weeks.

Bacterial infection: Bacterial infections are treated with a specific antibiotic depending on the type of bacteria and its location in the body. The accompanying fever in these cases is treated with painkillers and antipyretic drugs.

Vaccines: Some vaccines can cause a low-grade fever in the first couple of days post the injection. The fever is self-limited and disappears in a couple of days.

Environmental exposure to heat: Excessive exposure to the sun requires immediate attention to cool down the body. Loose clothing, sitting under a fan, cool mist, and antipyretic drugs can help bring down the fever. In its extreme form (hyperthermia), hospital care is required.

Fungal infection: Anti-fungal medications treat infections of a specific organ system and their accompanying fever.

Drug-induced fever: This fever is eliminated once the specific medicine is stopped.

Treatment available to treat fever?

In case of low-grade fever, you might not need external agents to lower the body temperature. Doctors believe that doing so only prolongs the illness and suppresses the actual symptoms of the underlying cause of fever. Many viruses that cause respiratory infections and colds thrive at normal body temperatures. Low-grade fever actually helps to eliminate these viruses.

High-grade fever can be treated with over-the-counter medication such as Ibuprofen, acetaminophen, and aspirin (aspirin must not be given to children as it can trigger a rare but fatal disorder known as Reye's syndrome). These medications must not be taken beyond their recommended doses as long-term usage of acetaminophen can lead to kidney or liver damage.

Your doctor may prescribe an antibiotic if s/he suspects the fever to be caused by a bacterial infection, like pneumonia or sore throat. Antibiotics, however, do not work on viral infections like stomach upsets (gastroenteritis). Though there are certain antiviral drugs available, the best treatment against viral infections is adequate rest and consumption of plenty of fluids.

Rest is essential for recovery, as extra activity will raise the body temperature. Fever leads to fluid loss and dehydration. Drink plenty of water and juices, and if you feel severely dehydrated, use an oral rehydration solution to bring the balance of fluids and electrolytes back to normal in your body. Soaking in lukewarm water or a sponge bath can also cool down high temperatures. However, stop the bath if it leads to shivering, as shivering again raises the body temperature.

If your fever was caused by exposure to sun and outdoors, stay cool in a room with moderate temperature and dress in light clothing.

When should you seek medical care for a fever?

Seek the help of a physician immediately in the following cases:

Temperature of 100.4 F (38 ^oC) in a child below three months of age.
Fever accompanied by other symptoms like vomiting, diarrhea, skin rashes could indicate more serious ailments like Dengue fever, rheumatic fever, chicken pox or strep throat.
Fever blisters on lips, mouth or tongue that turn into blisters are indicative of a first-time severe virus infection.

Apart from these situations, fever that accompanies a regular cold or infection can be treated symptomatically as described above. However, at any stage, if you encounter symptoms that do not corroborate with your earlier diagnosis, you should contact your doctor.