Learn about the causes, symptoms, and diagnosis of different types of fevers, such as dengue, malaria, typhoid, and rickettsia. Find out how to prevent and treat fever and when to seek medical help. Definition of Fever Studies have found that the maximum normal oral temperature is 37.2ºC (98.9ºF) at 6 A.M. and 37.7ºC (99.9ºF) at 4 P.M.; these values define the 99th percentile for healthy individuals. Hence, an Discover 12 common types of fevers, their symptoms, precautions, and effective treatments to help you stay informed and safeguard your health year-round.