1. Find an open space to avoid touching other objects while flinging the thermometer.
2. Hold the thermometer away from the mercury bubble so that the bubble is facing up.
3. Accelerate the thermometer and stop it when it reaches its lowest point. The mercury will continue to move downward under the effect of inertia and flow back into the mercury bubble. Please be careful during this operation, don't let the thermometer touch other objects, and don't let it slip out of your hand.
4. Repeat the process several times until the thermometer shows a temperature below 35℃.
Banning
Considering the mercury hazards of mercury thermometers, many countries have taken measures to ban them. As early as 1992, Sweden banned the sale of all medical devices containing mercury. Britain, France, Denmark and the Netherlands have also banned the use and sale. In the United States, 13 states and cities, including San Francisco, Boston and Michigan, have banned the sale of mercury thermometers since 2000.
The European Commission has also banned the sale of mercury thermometers since 2005 and their export since 2011, and in December 2008, the Argentinean government announced it would ban the production and import of mercury thermometers. The World Health Organization has also established the Global Mercury Elimination Program, which aims to reduce demand for mercury-containing thermometers and sphygmomanometers by 70 percent globally by 2017.
But mercury thermometers have not been banned in China. Mercury thermometers are widely used in the medical field and in ordinary households, and are available in some pharmacies. Data from the China Medical Devices Industry Association show that in 2008, the national production of mercury thermometers consumed 109.25 tons of mercury, which is equivalent to 21.85 billion standard mercury-containing energy-saving lamps.
According to statistics, about 120 million mercury-containing thermometers are produced in the country each year, and more than 10 tons of mercury are disposed of as waste in China each year due to broken mercury thermometers.
As of August 16, 2017, the Minamata Convention on Mercury came into force for China, which specifies that "the production of mercury-containing thermometers and mercury-containing sphygmomanometers will be banned from January 1, 2026."
Refer to Baidu Encyclopedia - Mercury Thermometers for the above