Take Merlin does not reduce fever, consider poor drug efficacy, insufficient body fluid or insufficient observation time after using Merlin, for the following reasons: 1. Poor drug efficacy: poor drug efficacy or insufficient dose of oral drugs. 2. Insufficient body fluid: antipyretic drugs reduce fever mainly through sweat secretion by sweat glands and evaporation of heat. Patients with fever have a poor appetite, wading and eating relatively little, so the body’s effective circulating blood volume is insufficient, resulting in no sweat or too little sweat secretion. For this part of the patient, should drink more warm water, if necessary, through the intravenous access to rehydration. 3, after the use of Merlin observation time is insufficient: antipyretic drugs in general, the onset of action is in about half an hour to two hours. During this time, the patient’s temperature and general state need to be closely observed, and it is not recommended to blindly add or change medication. If the observation time exceeds four hours and the body temperature still does not drop, go to the hospital.