Which would be best for the nurse to use when determining the temperature of a preterm infant under a radiant heater?

A) Axillary sensor
B) Tympanic membrane sensor
C) Rectal mercury glass thermometer
D) Rectal electronic thermometer

The axillary sensor measures the infrared heat energy radiating from the axilla. It can be used on wet skin, in incubators, or under radiant warmers. Ear thermometry does not show sufficient correlation with established methods of measurement. It should not be used when body temperature must be assessed with precision. Mercury thermometers should never be used. The release of mercury, should the thermometer be broken, can cause harmful vapors. Rectal temperatures should be avoided unless no other suitable way exists for the temperature to be measured.