If you want to disguise a fever with a thermometer, since the body temperature of a normal person is 36.3-37.2°C, a person who does not have a fever will certainly not be able to measure a body temperature above 37.5°C. If you want to fake a fever, you should prepare a small bottle, pour hot water on it, and then clip it under the armpit when you take the temperature, which will certainly help to raise the body temperature and may fake a fever successfully. However, it is recommended that those who are ill and seek medical attention, cooperate with professional doctors to clarify the cause of the disease for treatment, and those who are not ill are advised to take some other methods.