A clinical thermometer is a medical device used to measure body temperature. It helps determine if a person has a fever or is experiencing other health issues. These thermometers can be digital or glass, with digital versions providing quick readings and glass thermometers using mercury or alcohol to indicate temperature. Clinical thermometers are commonly used in hospitals, clinics, and homes. They can be placed under the tongue, in the armpit, or rectally, depending on the method chosen. Accurate temperature readings are essential for diagnosing illnesses and monitoring health conditions, making clinical thermometers an important tool in healthcare.