Why is your body temperature usually at 99 degrees Fahrenheit at night?

Body temperature typically fluctuates throughout the day due to the body's circadian rhythm, which regulates various physiological processes. At night, the temperature generally drops to promote sleep, but it can still hover around 99 degrees Fahrenheit for some individuals due to factors like hormonal changes, metabolic activity, and individual variations. This slight elevation can also be influenced by factors such as physical activity or the ambient temperature of your sleeping environment.