The infection causes a rise in body temperature which is more than the normal temperature. This condition is called fever. The normal body temperature is considered to be 37°C. The immune system produces chemicals that cause a bacterial or viral infection. The infection increases the temperature of the body. There can be many reasons behind fever, both serious and non-serious. Some of them are urinary tract infections, malaria, common cold, gastrointestinal infections, chronic illness, tropical diseases, drugs, heatstroke, infectious tumors, etc. Fever can happen due to non-infective reasons as well. Some fevers need medication, like antibiotics whereas, some others stop on their own after some time.