Thermometer for fever testing

Which type of thermometer is best?

• Digital stick thermometer: inexpensive and accurate. Use it in the mouth for older children and adults, under the arm for a quick check, or rectally for babies.
• Forehead (infrared) thermometer: fast and comfortable, even for a sleeping child, but readings are affected by sweat, a cold or air-conditioned room, or holding it at the wrong distance. Follow the instructions exactly.
• Ear thermometer: quick and accurate when placed correctly, but not recommended for babies younger than 6 months because their ear canals are too small.

Choosing a baby thermometer

For babies under 3 months, a rectal reading with a digital thermometer is the most accurate. Keep a separate thermometer for rectal use and label it. For older babies and toddlers, an armpit reading or a forehead thermometer is easier; if a reading is borderline, confirm it with a second method.

What counts as a fever?

A temperature of 38°C (100.4°F) or higher is generally considered a fever, and armpit readings tend to be a little lower than oral or rectal ones. Contact a doctor straight away if a baby under 3 months has a temperature of 38°C or higher, or if anyone with a fever has trouble breathing, a stiff neck, a rash that does not fade when pressed, unusual drowsiness or signs of dehydration. During the dengue season in Bangladesh, see a doctor early for any high fever, and urgently if there is severe stomach pain, repeated vomiting, bleeding from the gums or nose, or extreme tiredness.

Tips for accurate thermometer readings

Wait 15 to 20 minutes after eating, drinking or bathing before taking an oral reading. Check that the thermometer is set to °C: many models sold on Amazon default to °F but can be switched in the settings. Replace the battery when the low-battery symbol appears, because a weak battery can give false readings.