To measure the temperature in the oral cavity, use a mercury thermometer with a long pointed end. Treat it with an alcohol solution and place on either side of the sublingual frenulum. During the procedure, breathe through your nose and don't talk, otherwise the indications of the thermometer will be inaccurate due to exposure to low ambient temperature.
Remove the thermometer after 3-4 minutes. The temperature in the mouth is different from the temperature in the armpit by about 0.5 degrees, so a slight excess the mark of 37 degrees is acceptable. If the thermometer is above 37.3 degrees, you need to contact the doctor to find out the reason for the rejection and recommendations.
This method of temperature measurement is not suitable for children of preschool age and people with unstable mentality. Accidental damage of the glass tip of the thermometer is unsafe. Replacement for the mercury thermometer is an electronic thermometer that allows you to take temperature readings in seconds.
After preprocessing of the tip of the electronic thermometer with the alcohol place it in your mouth the same as you would with a mercury thermometer. Speed measurement in this case will be much higher. Already after 15-30 seconds (depending on the model of the thermometer in 60 seconds), an audible signal indicating that the measurement is complete.
After using the pack the thermometer in a plastic case which comes with both mercury and electronic thermometers.
Temperature measurement in the mouth immediately after eating is pointless. The result will depend more on the temperature of food eaten than on the objective condition of the person. Smoking may also distort the result. If there is no opportunity before the procedure to wait at least an hour, refrain from measuring the temperature orally.