Final answer:
A clinical thermometer should be left in the axillary site for 5-7 minutes to ensure an accurate measurement of body temperature.
Step-by-step explanation:
When using a clinical thermometer to measure body temperature at the axillary site (underarm), it should typically be left in place for 5-7 minutes. This duration ensures that the thermometer has enough time to accurately register the body's temperature. Axillary temperatures are known to be slightly lower than oral or rectal temperatures, so it is crucial to leave the thermometer in place for the appropriate amount of time to achieve an accurate reading.