Why a thermometer highest only 42 ℃?

The highest scale only mercury thermometers to 42 ℃. This is because the temperature is more than 42 ℃, the person can't survive. Caused by a cold fever, mainly in order to improve the body temperature to kill bacteria enter the body, but once more than 42 ℃ temperature, the main composition of body protein would like boiled egg protein coagulation, cure. As cooling could no longer get setback after eggs boiled egg, once the body protein is curing is unlikely to recover, nature also can't continue to life. As a result, even appeared in the thermometer scale of more than 42 ℃, is completely unnecessary. Scientists are also in the dry air environment, to the human body can endure made experiment: the highest temperature in nude cases, the body can stand fast temperature limit of 210 ℃; And put on a thick winter flight suit, it limits the human body can endure a sudden warming of up to 270 ℃. But, the body temperature was unbearable. If temperature is more than 42 ℃, the function of the central nervous system occurs serious disorder, the body protein may be modified, solidification, will have life risk, so the thermometer highest degree only 42 ℃. For the human body, the temperature of 40 ℃ is a dangerous signal, 42 ℃ temperature leads to irreversible organ damage and even death.