In humans , normal body temperature ( oral ) hovers around 37C or 98.6F.
The human body’s thermoregulation is controlled by the hypothalamus in the brain. Temperature cycles are controlled by a persons circadian rhythm.
Body temperature of a healthy person varies during the day by about 0.5*C , with lower temperature in the morning and higher temperature in the late afternoon and evening. This depends upon changes in the body’s need and activity.
Normal body temperature varies slightly from person to person and by time of the day. Consequently, the range of normal body temperature lies between 36.3C to 37.3C (97.3F to 99.1F).
Body temperature may change when a person is sick, hungry, sleepy or cold. Various factors like exposure, hormones, metabolic rate and diseases affect normal body temperature.
Human body temperature is of interest in medical practice, human reproduction and athletics.