What type of thermometer measures temperature by being run across the forehead for about three seconds?

The correct answer is the temporal artery thermometer. This type of thermometer is specifically designed to measure body temperature by scanning the forehead over the temporal artery. It uses infrared technology to detect the heat emitted from the skin's surface, providing a quick and non-invasive measurement of body temperature within just a few seconds.

Temporal artery thermometers are particularly useful in clinical settings because they allow for easy and fast temperature readings without the discomfort of inserting a device into the mouth, rectum, or under the arm. They are also hygienic, as they do not require direct contact with body fluids.

Understanding this technology is key for CNAs, as they often need to assess patients' temperatures quickly and effectively, especially in situations where rapid assessments are critical, such as in emergency care or pediatric settings.