Temperature refers to the body's internal temperature. Normal axillary temperature is 30 - 37 degrees, 0.2 higher than an oral temperature under 0.4 degrees, the rectal temperature than the oral temperature high 0.3 - 0.5 degrees. The body temperature is normal relatively constant temperature fluctuate slightly in 24 hours, generally are not more than 1 degrees. Under physiological conditions, the body slightly lower degree of morning, afternoon slightly higher. Exercise, after eating, women's menstrual period before pregnancy or temperature is slightly higher, while the elderly low body temperature. Temperature is higher than normal called fever, 37.5 - 38 for fever, 38 - 39 degrees for moderate fever, 39 - and 40 degree fever. 40 degrees above ultra high fever. The body temperature is relatively constant is one of the important conditions to maintain the body's normal life activities, such as the temperature is above 41 degrees or below 25 degrees will seriously affect the system (especially the nervous system) function, and even endanger life. Heat production and heat loss of the body, is God Central regulation and many diseases can make the body temperature normal regulation function obstacles and make the body temperature change. Clinical on patient body temperature and rare view the changes of disease diagnosis and judgment of certain diseases has important prognostic significance.