THE OBSERVATION OF THE VARIATIONS OF TEMPERATURE IN FEVER.
All fevers do not behave alike. In any given case of fever the temperature does not always remain at or about the same level throughout the course of the disease. It varies from day to day, and maybe from hour to hour. In nearly all cases there is a period of onset, a period during which the temperature is at its height, and a period of decline. The period of onset is usually indicated by chilliness, or a shivering-fit, a rigor as it is called. Even in this stage, when the skin may feel and look cold and even livid, the temperature, if taken by the thermometer, will be found raised. During the period when the fever runs at its height, there are still always oscillations, and the period of decline may be sudden and marked by an out break of sweating, diarrhoea, or other circum stances, in which case it is called a crisis. In other cases the fever may only gradually loosen its hold, and this is called lysis.
Now the temperature in many fevers, and specially the specific fevers, has characteristic modes of onset, has ways peculiar to each special fever of working up to its acme, and, if unimpeded by complications, ends also in typical ways.
The behaviour of the temperature will, then, often be sufficient to indicate the nature of the ailment from which the patient is suffering. In other words, the temperature in many dis eases pursues a regular course distinguishing it from temperature due to other causes, and in a few cases the course is so characteristic that the nature of the malady is recognized from it alone, even after only a day or two's observation.
Methodical observation, however, is neces sary to distinguish disease thus, and if the temperature, taken at certain regular intervals, be so noted on a chart as to be represented to the eye in the shape of a curve, the recognition of the disease is much more easy.
Temperature the purpose of recording temperatures in a graphic way, charts are prepared which the figures illustrate. These charts may be designed, as that in fig. 201, for
recording the morning and evening tempera ture of each day. In such a case the tempera ture must be taken at the same hour, say 9 a.m. and 9 p.m. But there may be a two hourly chart, or three-hourly, or four-hourly, and so on (Plate XXVI.). The two-hour chart may be made to record the temperature each hour by the line dividing off the spaces being utilized. It will be noted that the temperature is marked in the Fahrenheit scale on the left, and on the right the corresponding figures of the Centigrade scale are noted. In the plate the amount of fever according to the latter scale is marked in brackets below the Fahrenheil figures. In each case the level of the normal temperature is marked by a heavy black lint from left to right. Above this and below h a fine line corresponding to each increased degree of temperature. Between every two of these lines, marking 1 degree, are four fine lines making five narrow spaces between each degree. Each of these lines, therefore, indicates 2th of a degree, and the space between will indicate half of this, that is or 0.1 of a degree. Thus the heavy black line above 98°, marking the normal temperature, occupies the position of the second fine line above 98°, that is 98 or 98'4; the space above that will be 98'5°, and the fine line above it 98.6° and so on, till 99° is reached. Then in the chart (Fig. 201) the two spaces headed M. and E., meaning morning and evening, make one (lay, and every seven of these double columns is marked off by a heavy vertical line, so that weeks are seen at a glance. At the foot of each double column is a space for the date, a space for the day of the disease, and two other spaces for noting pulse and tem perature. These last two are divided diagon ally to permit more space for the entry of the figures indicating the morning and evening pulse and morning and evening rate of breath ing, the upper of the two spaces being in each case used for the morning figure.