Chills - cold feeling, accompanied "gooseflesh" (see), the reduction of skeletal muscles (tremors), the cessation of sweating, increased allocation of urine and blood sugar levels. Fever occurs when a sudden temperature rise, and during cooling. Fever develops as a result of a sharp spasm of the blood vessels of the skin and reducing the amount of blood circulating in them, which leads to a subjective feeling of cold and breach of heat transfer (see Thermoregulation). Chills observed in many infectious diseases and suppurative processes in tissues. Vomiting also occurs when parenteral introduction of alien protein and blood for transfusion is incompatible group.