The normal range is 96.8 for a body temp,and this usually occurs at rest when the person is not active. The temperature is maintained by the balance,,and the regulation between heat loss and heat gain.This is the humans body thermostat which keeps the core temperature.(hypothalamus).
When its hot outside the body becomes warmer ,and the body temperature rises towards the normal skin temperature.This makes it harder to eliminate the heat factor.
Since a person can not loose the heat fast enough they become hotter, the area a person is in, and it reaches or exceeds 91 and the heat is not lost ,the body must adjust by sweating to increase evaporation.
Fevers usually occur with infections, and are a huge defense mechanism for the body-- Its a symptom that the body is fighting off something.
There are several reasons to get fevers but all include infection...When the body's thermostat is upset a fever usually occurs. The brain detects the infection with the blood that flows about (blood temperature)then it can use a series of controlling vales in the blood circulation to act on the temperature and adjust as necessary untile it reaches the value for which the temperature is set.
Asprin work by stopping inflammation asprin block the effects of certain enzymes that cause prostaglandins.
Fevers let a person know an issues is in progress with in or on the body.
The immune system works with the fevers and helps fight infections and strengthens the body. With increased temperature the (CD8+ cytotoxic -T Cells) with this the body can fight harder to improve the immune system.
The increase in core temperature elevates neutrophils that selectively target infectious Bacterical cells.
This improves enzymatic activy to make the environment that is not liked by the infectious microbes.