Fever in the elderly that does not subside after physical cooling or medication is commonly seen in clinical situations where the condition is severe or not treated for the cause. In order to avoid aggravation or prolongation of the condition, the specific cause of the fever should be clarified as soon as possible after the elderly have a fever, and the corresponding treatment should be carried out. I. Not treating the cause of the fever The main measure to reduce fever is to treat the cause of the disease. If the drug is not applied correctly, it will lead to non-reduction of fever. If the cold is caused by bacteria or virus, the effect of reducing fever is usually not achieved by physical cooling alone. If drugs are used indiscriminately without clarifying the cause, such as antiviral drugs for fever caused by bacterial factors, it can also lead to a fever that does not subside. Second, drug-resistant bacteria infection pathogenic microorganisms resistant to drugs, such as not to do drug sensitivity tests, blindly use drugs, not only does not cure the disease, the temperature does not go down, but also cause adverse reactions. Third, the secondary new infection after the control of the original disease, the secondary new pathogenic microbial infection or overlap infection, and cause fever again or repeated fever. A few elderly patients can develop fever after taking a certain drug for 7-10 days, and the fever will not subside. Most patients only show fever with other symptoms such as drug allergy, and the body temperature will gradually return to normal after stopping the drug.