Especially in winter, when people swim in winter, when they enter cold water, their warm bodies will feel a thrill and contract.

The blood vessels on the surface of the body will contract, and people will feel insufficient blood supply, dizziness and headache.

If you have physical problems (cardiovascular and cerebrovascular diseases, heart disease, hypertension, epilepsy, etc. ) Those that don't meet the requirements of winter swimming will be obvious to you.