Which factor may influence oral temperature readings?

Oral temperature readings can be influenced by several factors, and smoking is one of the most significant among them. When a person smokes, the heat from the smoke can temporarily increase the temperature in the mouth, leading to higher readings. This effect can distort the accuracy of the oral temperature measurement if taken shortly after smoking. It is generally advised to wait at least 15 to 30 minutes after smoking before taking an oral temperature to ensure a more accurate reading.

Other factors, such as drinking hot or cold beverages or even chewing gum, can also impact oral temperature readings but are not mentioned in this question. While speaking or environmental conditions like the weather can have some minor effects, they are not as pronounced as those caused by smoking.