Your child appears flushed and you wonder if she has a temperature. Putting your hand on her forehead you get a quick read that her skin feels hot. In the bathroom, you have an assortment of mercury thermometers, forehead strips and a temporal artery type. So which thermometer should you use?
Mercury thermometers are the most traditional method for measuring temperature. Rectal thermometers are the most accurate but are typically only used on infants or small children. They will show the body temperature as being up to a degree higher than other methods because they measure core body temperature.
Oral mercury thermometers must stay in place under the tongue for a full five minutes in order to get an accurate reading. Some people check a temperature by using a mercury thermometer under the arm but this is not a reliable way to take a temperature especially on a squirming child. All mercury thermometers risk breakage making them a less popular way to check body temperature.
Skin thermometers are popular because they are quick, inexpensive and easy to use. There are two types of skin thermometers: forehead strips or temporal artery. Forehead strips are a quick way to get a ballpark idea of a child’s temperature. They work by allowing the skin temperature to heat the liquid crystals in the strip. The color change is correlated to a different numbered temperature on the strip. If the strip temperature is elevated, it is best to recheck it with a mercury thermometer.
Temporal artery thermometers are more accurate but more expensive. They cost about $30 to $150 dollars and can be purchased a drug stores or online. Temporal artery thermometers have a metallic head that is rolled across the forehead to read the temperature using infrared light.
Temporal artery thermometer are also temperature sensitive themselves which can affect accuracy. The devices must be used at room temperature and can be affected by other light heat sources close to the person whose temperature is being measured. If the person has been sweating, the temperature reading can be affected as evaporation of sweat cools the skin giving a false low reading.