When antibiotics are applied to the body, the body temperature may rise again. The main reason is that antibiotics are allopathic treatment, and if the cause of the fever is bacteria, the bacteria can only be controlled after the antibiotics have been used for a longer period of time to completely kill the cause of the disease, and then the symptoms of elevated body temperature can be gradually controlled. The time it takes for antibiotics to act on the body and kill the bacteria completely is likely to be slightly longer, from one or two days for short ones to three or four days for longer ones. Therefore, if you want to judge the effectiveness of antibiotics by the rise in body temperature after applying them, you need to wait at least two days, and in some cases, even four days, before you can see the effect.