- Check that the thermometer lens is perfectly clean. If in doubt, clean the lens with a cotton swab lightly moistened with alcohol. After cleaning, wait 30 minutes before measuring again.
- Check that there is no hair, sweat, cream or other cosmetic products on the forehead surface.
- Make sure that the thermometer is at the same room temperature as the person on whom the measurement is taken for at least 30 minutes.
If in doubt, check the temperature with a conventional thermometer and/or consult your doctor.