Recently, an event called the “Ice Bucket Challenge” spread from the United States to China and immediately attracted a large number of celebrities to participate. It is said that this activity is to raise awareness of the rare disease Amyotrophic Lateral Sclerosis (ALS, commonly known as “progressive freezing”). The “Ice Bucket Challenge” was launched in the United States and requires those named to splash a bucket of ice water on themselves within 24 hours, take a video and designate the next three people to accept the challenge to repeat the process. If you do not accept the splashing of ice water, you have to donate $100. Many domestic and foreign celebrities such as James, Kobe, Lionel Messi, C Luo, Li Bingbing, Jay Chou, etc. have participated in it. Even U.S. President Barack Obama has been named, only he politely declined the ice bucket and chose to donate $100 directly. And the general public, driven by the stars, also actively participated in this activity. But in fact, not everyone is suitable for the “ice bucket challenge”, especially patients with cardiac arrhythmia, must say “NO” to the activity. First of all, the sudden cold stimulation will activate the sympathetic nerves in the body. Sympathetic excitement can easily induce supraventricular tachycardia, premature ventricular beats, ventricular tachycardia, atrial fibrillation and other types of arrhythmias. Secondly, cold tends to cause vasoconstriction. The contraction of cardiac blood vessels can cause ischemia in the heart, and if it is combined with coronary heart disease, it can even induce “myocardial infarction” or “malignant arrhythmia”. In addition, vasoconstriction can also induce various complications of hypertension, such as stroke, fundus hemorrhage and so on. Therefore, all kinds of heart patients are very unsuitable for the “ice bucket challenge”, even if they are “named”, they should calmly say “NO”!