Sometimes, due to weather changes the thermometers get decalibrated and need to be reset.
Perform the following steps to reset your thermometer:
1. Remove the batteries from your thermometer
2. Store thermometer at room temperature (Avoiding placing thermometer in direct sunlight or in front of AC vents) for at least 1 hour
3. Re-insert batteries
4. Power thermometer on - your thermometer should briefly display the room temperature and be ready for the intended use.
Please note: When recording a temperature, the thermometer must be placed on the forehead or inside of the ear before pressing the button to take the temperature is selected. If you press the button first, the thermometer will begin to read the temperature of the air that it is exposed to, interfering with the head or ear temperature; resulting in an inaccurate reading.
please reassure that your thermometer sensor is clean off as well
to do that please remove the cam and clean tip of the sensor with a microfiber towel or a cotton swab.