The summer weather is hot, and people with poor physical condition are very likely to suffer from heatstroke if they stay in the high temperature weather for a long time. However, we can not know when and who will get heatstroke, and we can not prevent it. But today's heatstroke alarm is fresh enough. It can measure the temperature and humidity of the surrounding environment and estimate the possibility index of heatstroke, and the display can directly react the value. Moreover, the LED light on the alarm can indicate different levels of heatstroke index and issue warnings. In this way, we can well prevent heatstroke.