What are possible “pitfalls” to be recognized with any thermometry technique, depending on the measurement site?

Most temperatures taken in medical settings are subject to wide variations depending upon the following elements:

• Expertise of the operator: proper placement, dwell  time, technique, use of clean/new probe covers each time
• Temperature of the thermometer itself should  be stable; ambient adjustment circuitry
•  Ambient and Patient conditions: A/C vents, heaters, air movement against skin, evaporative cooling in mucous membranes, mouth-breathing, recent ingestion of food or drink, presence of breathing tubes, nasal tubes, presence of fecal material in rectum, ear-wax buildup, etc.