The child bites the head of the thermometer, may be mercury poisoning, stabbing the oral cavity, damage to the gastrointestinal tract and other dangers. Currently commonly used thermometer is generally made of mercury, thermometer head after biting, may accidentally eat mercury caused by mercury poisoning, this is a more dangerous situation, it is recommended to seek medical attention. The thermometer is made of glass, after biting the broken glass is easy to stab the oral cavity, you can carefully check the oral cavity for bleeding, or the oral cavity for broken glass, clean up in a timely manner, clean and disinfect the broken parts. The child cries after the puncture, may swallow the broken glass, this is also a more serious situation, may scratch the esophagus, stomach, intestines, etc., need to carefully check the thermometer with or without defects. Still the head of the thermometer may be potentially dangerous after biting it to pieces, it is recommended to take the child to the hospital as far as possible.