Clinically the temperature is estimated by means of a self-registering thermometer placed, for from one to five minutes, in close contact with the skin in the axilla, or in the mouth. Sometimes the thermometer is inserted into the rectum, where, however, the temperature is normally ¾° F. higher than in the axilla. _In health_ the temperature of the body is maintained at a mean of about 98.4° F. (37° C.) by the heat-regulating mechanism. It varies from hour to hour even in health, reaching its maximum between four and eight in the evening, when it may rise to 99° F., and is at its lowest between four and six in the morning, when it may be about 97° F. The temperature is more easily disturbed in children than in adults, and may become markedly elevated (104° or 105° F.) from comparatively slight causes; in the aged it is less liable to change, so that a rise to 103° or 104° F. is to be looked upon as indicating a high state of fever. A sudden rise of temperature is usually associated with a feeling of chilliness down the back and in the limbs, which may be so marked that the patient shivers violently, while the skin becomes cold, pale, and shrivelled--_cutis anserina_. This is a nervous reaction due to a want of correspondence between the internal and the surface temperature of the body, and is known clinically as a _rigor_. When the temperature rises gradually the chill is usually slight and may be unobserved. Even during the cold stage, however, the internal temperature is already raised, and by the time the chill has passed off its maximum has been reached. The _pulse_ is always increased in frequency, and usually varies directly with the height of the temperature. _Respiration_ is more active during the progress of an inflammation; and bronchial catarrh is common apart from any antecedent respiratory disease. _Gastro-intestinal disturbances_ take the form of loss of appetite, vomiting, diminished secretion of the alimentary juices, and weakening of the peristalsis of the bowel, leading to thirst, dry, furred tongue, and constipation. Diarrhœa is sometimes present. The _urine_ is usually scanty, of high specific gravity, rich in nitrogenous substances, especially urea and uric acid, and in calcium salts, while sodium chloride is deficient. Albumin and hyaline casts may be present in cases of severe inflammation with high temperature. The significance of general _leucocytosis_ has already been referred to. #General Principles of Treatment.#--The capacity of the inflammatory reaction for dealing with bacterial infections being limited, it often becomes necessary for the surgeon to aid the natural defensive processes, as well as to counteract the local and general effects of the reaction, and to relieve symptoms.