Infection. Infants and toddlers usually get fevers due to their bodies response to an infection (usually viral or bacterial). Substances are secreted by your body when fighting an infection that changes the thermostat in your brain (hypothalamus) to increase the temperature of the body. The fever is helpful for the body to fight infection.
Reaction with germs. Infants' and toddlers' fevers are often from infections. Germs such as viruses and bacteria interact with a child's immune system . . . Resulting in fever. Fevers may also occur from non-infection types of illnesses, but these illnesses are uncommon. A doctor can help decide the cause of a fever.
To Kill Germs. Fever is your body's way of killing germs. It is a natural and important response to infection. Check out http://www.Youtube.Com/watch?V=q83hamgyc6c and http://www.Youtube.Com/watch?V=zkoevqtnkis.
Immune response. Fever is a response to infection. My simplistic explanation is that the immune system raises the thermostat to cook the germ out of the body.Many times the infection (viral or bacterial) will burn itself out after a few days. The immune system is pretty amazing. If the fever persists or continues to rise, see a pediatrician to make sure infection has not progressed to needing intervention.