In the course of the first three days, the _temperature_ may rise to 100° F. in a case entirely normal. It has no pathological significance unless persistent or increasing. The temperature should be taken night and morning, and in complicated cases every four hours. All temperatures over 100° F., after the initial rise and descent just described, must be regarded as septic. The _pulse_ does not rise with the temperature of the first three days, but remains firm or even falls a little. When the pulse rises and the temperature sinks, it means hæmorrhage. The _urine_ is usually increased for the first few days and then returns to the normal for that patient. The labor affects the patient like a surgical operation. The _digestion_ is disturbed. The appetite is gone, and the stomach must be treated gently until its tone is restored. The body in repose is less urgent in its demands for food. Liquids in abundance form the staple diet for the first two days. For the next three days, semisolids may be added, and after the milk is well established, a general diet is desirable; but so long as the mother nurses her child, the liquids must preponderate in most cases. [Illustration: Fig. 60.—The progress of involution on the various days of the puerperium. (von Winchkel, from Knapp.)] Meanwhile, certain changes are taking place in the pelvis that are highly important. =Involution= is the process undergone by the uterus in returning to its normal nonpregnant state. This shrinkage can be followed abdominally and is registered by the nurse in the number of finger-breadths or centimeters above the symphysis pubis. Edgar gives the rate of shrinkage as follows: After delivery, 5.92 in. long, or 15.8 cm. 2nd day, 4.63 in. long, or 11.30 cm. 3rd day, 4.37 in. long, or 11.10 cm. 6th day, 3.42 in. long, or 8.48 cm. 8th day, 2.55 in. long, or 6.40 cm. 10th day, 2.22 in. long, or 5.60 cm. The rate of involution not only varies greatly with different women, but varies much after the different labors of the same woman. Ordinarily at the end of the first week the fundus should lie midway between the navel and the pubes, and should shrink rapidly thereafter. The necessity for watching the rate of involution is imperative for a number of reasons. If involution is slow, or stops, it may indicate fatigue of the muscle from multiparity or over-distention (twins, hydramnios, etc.) or it may follow a post partum hæmorrhage. Subinvolution may also indicate infection, the retention of clots, or pieces of placenta. It happens also when the woman gets up too soon or does not nurse her child and thereby delays the restoration of her waistline, as well as diminishes her resistance to disease. =The binder= is objectionable to some doctors on the ground that it favors retroversion of the uterus during involution.