Hello: Thermometers are commonly used medical devices, especially mercury thermometers are most commonly used. With this thermometer to measure body temperature, more than three parts of the human body, but their respective temperatures are also different, anal temperature - the measured body temperature is slightly higher; oral temperature - the middle value; axillary temperature - the surface temperature, the measured temperature readings are slightly lower, that is, the armpit temperature - the body temperature is slightly higher than the surface temperature, the measured temperature readings are slightly lower. -This is the surface temperature, and the measured temperature reads slightly lower, or 0.2-0.3 handfuls of degrees. If you put the thermometer around your neck, it should also be clipped in a leather fold, with the mercury end not exposed, and in fact a time of 5 minutes or so is sufficient. There is no need to make up the difference in the reading, just say which part of the body temperature was measured professionals will understand and can determine if there is a fever.
Currently there are electronic thermometers that are much more convenient.
The answer is not sure if it meets your requirements. Just for reference, I guess.