Mercury Thermometers Thermometers register temperature.
Many thermometers contain mercury, a silver-colored liquid.
Glass thermometers are extremely fragile and can be easily broken, allowing the mercury to escape. Accidental mercury releases in the home present some of the greatest poisoning risks to children. Mercury-containing thermometers should never be thrown in the trash or put down the drain or in the toilet. A typical fever thermometer contains about gram of mercury. A larger thermometer will have as much as 3 grams.