The 2024 National Master's Entrance Examination will be held from December 23rd to 25th, 2023. In order to prepare for the exam, a student in Xi'an, Shaanxi Province wore a purchased electric shock alarm clock on his lap to remind himself to wake up on time. Unexpectedly, the person was awakened, but the thigh was electrocuted and the alarm clock electrocuted, causing the skin to break. So, what is an electric shock alarm clock? Is it harmful to the body? The reporter from Science and Technology Daily interviewed relevant experts on this matter. "Electric shock alarm clock generally refers to an electric shock watch alarm clock, also known as a smart pulse watch. Unlike ordinary alarm clocks that awaken users through sound, electric shock alarm clocks stimulate the human body by releasing tiny pulse currents, thereby achieving the purpose of awakening." Zhou Guanggang, Associate Professor of the School of Science at China University of Petroleum, told Science and Technology Daily reporters. "Electric shock alarms are generally awakened in three stages," Zhou Guanggang explained. Firstly, the watch attempts to awaken it through a slight vibration. If the watch system finds that vibration cannot successfully wake up the user, it will start the second stage - waking up through a harsh sound. If the user still decides to "sleep for another 5 minutes" at this time, then an electric shock is coming. The shock intensity of an electric shock watch is generally adjustable. When subjected to low-intensity electric shock, users may feel similar to being subjected to static electricity, but if the electric shock intensity is very high, it may cause users to experience very strong pain. So, is electric shock alarms harmful to the body? There are slight differences in the parameters of electric shock alarms produced by different manufacturers. The output voltage of an electric shock alarm clock is usually between 16 volts and 150 volts, and the maximum output current is generally around 10 milliamperes. The safe current for the human body is about 10 milliamperes, and the maximum allowed current is 36 milliamperes. Exceeding 36 milliamperes carries a risk of death. Before purchasing an electric shock alarm clock, consumers should carefully check its current parameters. "If the designed current of an electric shock alarm clock is lower than the lethal current of the human body, there is generally no fatal danger. However, prolonged exposure to electric current can produce a thermoelectric effect, which may lead to local electric burns." Zhou Guanggang added that long-term and frequent exposure to weak electric currents may also change the normal potential difference of the human body, affect the normal electrophysiological processes of the myocardium, or cause dizziness and vomiting. In addition, patients with cardiovascular disease, skin allergies, or physical discomfort should not wear electric shock alarms. Author: Epic (Le Xin She)