Final answer:
Tongue depressors should be used with caution to prevent the spread of germs and infections.
Step-by-step explanation:
An important reason why you shouldn't let a doctor put one of those sticks in your mouth is because it can potentially spread germs. These sticks, also known as tongue depressors, are used to examine the mouth and throat. However, if proper hygiene procedures are not followed, they can transfer bacteria or viruses from one patient to another.
To avoid this, doctors should always use new and sterile tongue depressors for each patient. This helps minimize the risk of cross-contamination and the spread of infections. So, it's essential to ensure that proper infection control measures are in place when using tongue depressors.