While 98.6 degrees F is considered a normal body temperature, it can fluctuate throughout the day based on a number of factors. Eating, drinking, smoking, exercising, taking a hot bath, experiencing strong emotions or feeling anxious, tired, worried or agitated are all some things that can affect your body's temperature.

Normal body temperature is considered to be 98.6 degrees F, if the temperature is measured orally. This temperature can vary, however, if the reading is taken rectally or via the armpit; measuring your temperature via the ear can provide an accurate measure of core temperature, but many ear thermometers are less reliable than probe thermometers.

Normal body temperature can fluctuate by as many as two degrees more or less, due to a wide range of factors. Some of the factors that can influence your body temperature include:

• Eating
• Smoking
• Drinking
• Vigorous physical exercise
• Bathing in hot water
• Experiencing strong emotions or agitated mental states

Body temperature also fluctuates throughout the day as a result of your normal circadian rhythms.

Exercising can affect your body temperature dramatically. If you exercise vigorously, your body temperature can go up by as many as three degrees F. Such an increase presents a danger to your health, which is why your body begins to sweat when your temperature goes up more than two degrees.

When you sweat, your body temperature drops back down to the safe range of 96.6 to 100.6 degrees F. This occurs when hot blood travels from your muscles to the surface of your skin, where your evaporating sweat cools it down. The cooled blood then returns to your muscles and organs, lowering your body temperature.