Whether your home contains small children or adults, a thermometer is an essential piece of home medical equipment. Used thermometers should be sterilized before usage, but are nevertheless safe. Thermometers are inexpensive and useful, and offer a reliable way to monitor the health of yourself or a loved one.
Body temperature is one of the primary vital signs of the human body, and indicates a variety of health conditions. It can be measured in several places, but the most common is under the tongue. Normal average body temperature is about 98.2 degrees Fahrenheit, but varies throughout the day by as much as half a degree. Elevated body temperature usually indicates the presence of a disease, because the body generates heat as it fights infection, but can also be due to skin inflammation or immunological disease. Lowered body temperature is usually caused by exposure to a cold environment or to alcohol consumption.
Thermometers come in two main varieties: digital and mercury thermometers. Mercury thermometers contain a volume of mercury in a bulb, attached to a hollow tube via a narrow opening. When placed in a patient’s body, the mercury expands and rises up through the tube. When the mercury has expanded to the maximum that the patient’s body temperature will allow, it stops rising and the thermometer is removed. As it cools, the mercury cannot fall back through the constricted entrance to the bulb, and remains in the tube to indicate the patient’s body temperature.
Mercury thermometers are not the safest choice of thermometer, however. In order to reset mercury thermometers after use, they must be shaken vigorously in order to force the mercury back down into the bulb. This poses health risks because mercury is toxic, and if the thermometer is accidentally dropped while being shaken, it may break. Exposure to liquid mercury or to mercury vapor is hazardous at best, and lethal at worst. For a safer choice of thermometer, use digital thermometers. These have largely come to replace mercury thermometers in health care settings, because they do not rely on mercury and pose less of a health risk.
