To check fever with a mercury thermometer, follow these steps:
- Clean the thermometer with cool, soapy water or rubbing alcohol before use.
- Hold the thermometer at the top and shake it downward to get the mercury level below 96°F (35°C).
- Place the bulb end of the thermometer under the tongue, in the armpit, or rectum (for infants and small children, rectal is most accurate).
- Keep the thermometer in place for about 3 to 5 minutes (5 minutes usually recommended for mercury thermometers).
- Keep still during the measurement and avoid moving the thermometer.
- Remove the thermometer and read the temperature by looking at where the mercury line stops on the scale (above 98.6°F or 37°C usually indicates a fever).
- After use, clean the thermometer again and shake the mercury back down for next use.
For oral measurement, close the mouth around the thermometer and breathe through the nose. For armpit measurement, place the bulb in the armpit and press the arm against the body. Wait the full time before reading the temperature to ensure accuracy. Mercury thermometers should be handled carefully since mercury is toxic if broken. This method provides a reliable way to check for fever at home using a classic mercury thermometer.
