46. The first impression of the cold wet sheet is disagreeable; but no sooner does the blanket cover the sheet, than the chill passes away, and usually before the packing is completed, the patient begins to feel more comfortable, and very soon the symptoms of the fever diminish. The pulse becomes softer, slower, the breathing easier, the head cooler, the general irritation is allayed, and frequently the patient shows some inclination to sleep. When the fever and heat are very high, the sheet must be changed on growing hot, as then it would cause the symptoms to increase again, instead of continuing to relieve them. The best way to effect this changing of the sheet is to prepare another blanket and sheet on another bed, to unpack the patient and carry him to the new pack, where the process described above is repeated. Sometimes it is necessary to change again; but seldom more than three sheets are required to produce a perspiration, and relieve the patient for several hours, or--according to the case--permanently. The changing of the sheet may become necessary in fifteen, twenty, twenty-five, thirty or forty minutes, according to the degree of fever and heat. In every new sheet the patient can stay longer; in the last sheet he becomes more quiet than before, usually falls asleep, and awakes in a profuse perspiration, which carries off the alarming symptoms. 47. A few minutes before the perspiration breaks out, the patient becomes slightly irritated, which irritation is removed by the appearance of the sweat. I mention this circumstance, to prevent his being taken out just before the perspiration is started. When he becomes restless _during perspiration_, he is taken from his pack and placed in a bathing-tub partly filled with cool or tepid water, (usually of about 70 deg.,) which has been prepared in the meanwhile; there he is washed down from head to foot, water from the bath being constantly thrown over him until he becomes cool. Then he is wrapped in a dry sheet, gently rubbed dry, and either taken back to his bed, or dressed and allowed to walk about the room. When the fever and heat rise again, the same process is repeated. 48. ACTION OF THE PACK AND BATH.--RATIONALE. The action of the wet-sheet pack is thus easily accounted for: