Fever is a natural response of the body that helps in fighting off foreign substances, such as microorganisms, toxins, etc. Body temperature is set by the thermoregulatory center, located in an area in the brain called hypothalamus. Body temperature is not constant all day, but actually is lowest at 6 A.M. and highest around 4-6 P.M. In addition, temperature varies in different regions of the body; for example, rectal and urine temperatures are about one degree Fahrenheit higher than oral temperature and rectal temperature is higher than urine. It is also important to realize that certain normal conditions can effect body temperature, such as pregnancy, food ingestion, age, and certain hormonal changes. Every parent has probably experienced this scenario: You wake up in the middle of the night to find your child standing by your bed, flushed, hot, and sweaty. Your little one's forehead feels warm. You immediately suspect that your child has a fever, but you're unsure of what to do next. Should you get out the thermometer? Should you call the doctor? Fever occurs when the body's internal thermostat raises the body temperature above its normal level. This thermostat is found in the part of the brain called the hypothalamus. The hypothalamus knows what temperature your body should be (usually around 98.6 degrees Fahrenheit, or about 37 degrees Celsius) and will send messages to your body to keep it that way. What Causes Fever? It's important to remember that by itself fever is not an illness - it's usually a symptom of an underlying problem. Fever has several potential causes: Infection: Most fevers are caused by infection or other illness. Fever helps the body fight infections by stimulating natural defense mechanisms. Overdressing: Infants, especially newborns, may get fevers if they're overbundled or in a hot environment because they can't regulate their body temperature. Immunizations: Babies and children sometimes get a low-grade fever after getting vaccinated. Although teething may cause a slight rise in body temperature, it's probably not the cause if your baby's or toddler's temperature is higher than 100 degrees Fahrenheit (37.8 degrees Celsius). The most effective initial treatment for fever is to sponge the person who is having a fever. Sponging can effectively relieve the person by bringing down the temperature slightly. It is important to understand the symptoms associated with a fever. Learn to recognize it so that you know exactly what you are dealing with when a fever occurs!