Significance

• According to the Merck Manual Home Edition, fever is a sign that the body has been infected with a virus, a bacteria, an allergen or parasites. It is one of the body's ways of fighting back against the invaders.
  
  

Other Symptoms

• Because there are so many causes for a fever that also produces headaches and body pains, a doctor will need to know about any other symptoms present in order to diagnose the cause.
  
  

Time Frame

• According to the Mayo Clinic, if anyone over two years old has a fever for more than three days, he needs to contact a doctor. The time frame is one day for any child under two years old.
  
  

Misconception

• According to the Mayo Clinic, a high fever does not always mean that the condition is life threatening. There are serious conditions such as lymphoma that can produce a low fever, headache and body pains.
  
  

Warning

• If the fever is accompanied by a stiff neck, nausea and/or a skin rash, go to the hospital immediately. You could have meningitis, which is potentially fatal.