A thermometer seems simple, but small mistakes can give confusing readings. Understanding basic use makes home monitoring more reliable.

For digital oral thermometers, avoid measuring immediately after hot or cold drinks. Wait at least 15 minutes. Place the tip properly under the tongue and close the mouth, breathing through the nose during measurement. Talking or opening the mouth affects results.

Ear thermometers must be positioned correctly in the ear canal; wrong angles can show false low values. They may not be ideal for very young children. Forehead (infrared) devices are convenient but sensitive to distance and sweat.

Always read the instructions for your specific device. Clean the thermometer as recommended, and keep spare batteries. Comparing readings from different types of thermometers (ear vs forehead vs oral) can be confusing; stick with one method for consistency when tracking a single illness.

Remember, numbers are just one part of the picture. How the person looks, behaves and feels is equally important. Very high or persistent fever, especially in children or older adults, should be discussed with a doctor.