Upon finishing the work the temperature quickly falls to normal, so that there is no reason at present for supposing this daily rise to be seriously harmful. In fever the production of heat becomes greater than its loss for a time and so the temperature goes up. It must not be forgotten that presently the loss again balances the production; if it did not, the temperature would keep on rising until death resulted; usually the greater loss of heat from the body at the fever temperature is sufficient to restore the equilibrium, but it will be clear that the temperature cannot fall again until the heat loss exceeds the heat production. There has been a good deal of discussion as to whether fevers are caused by an increase of heat production or by an impairment of the machinery for getting rid of heat. There is no doubt that in fevers the resting metabolism is much greater than in health; it is not by any means always the case, however, that the total metabolism of an individual lying quietly in bed with a fever is greater than that of a healthy individual doing heavy manual labor. We must therefore look to an interference with the process of losing heat to account for the rise in temperature. The distribution of blood through the skin in fever does not differ from that at other times when the body is warm; it is the usual thing in fevers for the skin to be much flushed. There is, on the other hand, a definite impairment of the sweat-secreting mechanism. It is one of the most familiar facts about fever that the skin is not only hot but very dry. It is also well known that by inducing sweating the temperature can often be brought down. It is evident that the poisons which are responsible for the fever have at least two effects; to increase general resting metabolism to a high level and at the same time to interfere with the ordinary regulation of the sweat glands, so that, even though the temperature of the blood is several degrees above normal, the sweat glands are not stimulated to active production of sweat.