Hello Bolaji! Thank you for using the #asksudrexfeature. A fever is the body’s way of fighting an infection (infections can be caused by viruses, bacteria, parasites, etc) by naturally raising your body’s temperature. It is completely possible for an adult to develop a fever with no other symptoms, & the cause of the fever often goes away on their own after a few days. However, seek medical care if your temperature is still very high or keeps coming back after taking fever medications like Sudrex Headache & Fever.