Of all the symptoms associated with the measles, fever is by far the most common, if not a guarantee. According to the Mayo Clinic, “Fever occurs when an area in your brain called the hypothalamus — also known as your body's "thermostat" — shifts the set point of your normal body temperature upward. When this happens, you may feel chilled and add layers of clothing or wrap up in a blanket, or you may shiver to generate more body heat, eventually resulting in an elevated body temperature.
“Normal body temperature varies throughout the day — it's lower in the morning and higher in the late afternoon and evening. Although most people consider 98.6 F (37 C) normal, your body temperature can vary by a degree or more — from about 97 F (36.1 C) to 99 F (37.2 C) — and still be considered normal.”
In the case of measles, especially when dealing with children, if they fever is high, the child should be kept cool, not cold. Tylenol or ibuprofen are effective measures to use in controlling fever, even in the case of measles.