Immersion in cold or ice water, either passively or actively by swimming, has become very popular. Many people use this method for health promotion, both mentally and physically, as well as an extreme environment for competitive swimming. Nevertheless, despite the popularity of this phenomenon, professional knowledge, science and practical regulations are lacking. On one hand, research findings tend to generally support ice water immersion or swimming for health and resilience, but on the other hand, it involves significant exposure to stress, which may expose participants to major risks, especially in the occurrence of certain risk factors. Studies in this field describe many different protocols, conditions, definitions and populations, making further quality and in-depth research necessary in order to develop a set of criteria for a useful, healthy, and safe practice. Assuming this phenomenon is here to stay, it is of great importance to educate medical staff and introduce up to date basic physiological and medical data, which is required for proper professional guidance, support and risk management.