The necessary precautions that must be taken when using thermometer include the following: make sure the liquid inside the thermometer is at eye level when taking taking the temperature and make sure the bulb of the thermometer does not touch the bottom of the beaker when taking the temperature.
Never use a thermometer as a stirring device, don't swing or shake down a thermometer and make sure the bulb of the thermometer is surrounded on all sides by the liquid which is to be measured.