We know that the fever is a temporary increase in our body temperature which is often caused by an illness. When someone has a fever, then this is a sign that something out of the ordinary is going in your body. If you are an adult, the fever can be uncomfortable but usually this is not a cause for concern unless your fever reaches 39.4 C (101.3 F) or higher. But for infants and toddlers, a slightly elevated temperature can indicate a serious infection. In the most cases, fevers are going away in a period of few days. There are many different over – the – counter medications which are lowering the fever but there are some cases when it is better to let it untreated. It seems that the fever plays a key role in the helping your body to fight off a number of infections.
Someone has a fever when his temperature rises above the normal range. What is normal for someone can be a little lower or higher that the average normal temperature of the body and that is 37 C (98.6 F). Depending on what is the cause for your fever, additional signs and symptoms can include:
- General weakness
- Loss of appetite
- Muscle aches
- Chills and shivering
Children who are between the ages of 6 months and 5 years can experience febrile seizures . There are some studies in which are said that about a third of the children who have one febrile seizure will have another one and most common this will happen in the next 12 months . If your child is listless or irritable and vomits repeatedly, then call his doctor. Also if he or she has a fever that lasts longer than 3 days, then call his doctor. If you have severe headache, persistent vomiting, mental confusion or you have unusual skin rash, especially if the rash rapidly worsens, then seek immediate medical attention.
Causes of fever
This condition is happening when an area in the brain called hypothalamus shifts the set point of the normal body temperature upward. Hypothalamus is also known as body’s thermostat. When this happens, then you can feel chilled and you will wrap in a blanket or add layers of clothing or you will shiver to generate more body heat which will eventually result in elevated body temperature. The normal body temperature varies throughout the day. It is lower in the morning and it is higher in the late afternoon and evening. Many people consider that the 37 C (98.6 F) is normal body temperature, but the body temperature can vary by a degree or more – from about 36.1 C (97F) to 37.2 C (99 F) and this can be still considered as normal body temperature. A fever or elevated body temperature can be caused by:
- Some immunizations, such as diphtheria, tetanus and acellular pertussis (DTaP) or pneumococcal vaccine
- Some medications, such as antibiotics and drugs used to treat high blood pressure or seizures
- A malignant tumor 
- Certain inflammatory conditions such as rheumatoid arthritis – inflammation of the lining of your joints (synovium)
- Heat exhaustion 
- A bacterial infection 
- A virus 
There are some cases when the cause of fever cannot be identified. If you have a fever for more than 3 weeks and your doctor cannot find the cause for your fever after he had made tests, then the diagnosis can be fever of unknown origin.
Complications: Children that are between the ages of six months and five years can experience fever – induced convulsions (febrile seizures) which are usually involving loss of consciousness and shaking of limbs on both sides of their body [1,2]. This is an alarming condition for the parents but the vast majority of the febrile seizures are causing no lasting effects. If a seizure happens:
- Do not place anything in your child’s mouth or try to stop the seizure
- Hold your child to prevent injury
- Loosen tight clothing
- Remove any sharp objects that are near your child
- Lay your child on his or her side or stomach on the floor or ground
In the most cases, seizures will stop on their own. You should take your child to his or her doctor as soon as possible after the seizure because he must find out which is the cause of the fever. If the seizure last longer than 5 minutes, then you should call for emergency help.
 National Institute of Neurological Disorders and Stroke. Febrile seizures fact sheet. Retrieved from www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Febrile-Seizures-Fact-Sheet
 Baumann RJ. Pediatric febrile seizures. 2018. Retrieved from emedicine.medscape.com/article/1176205-overview
 Foggo V, Cavenagh J. Malignant causes of fever of unknown origin. Clinical Medicine. 2015;15(3):292–4.
 Glazer JL. Management of heatstroke and heat exhaustion. American Family Physician. 2005;71(11):2133-40.
 Plaza JJG, Hulak N, Zhumalidov Z, Akilzhanova A. Fever as an important resource for infectious diseases research. Intractable & Rare Diseases Research. 2016;5(2):97–102.