The idea of the shock pool is borrowed from the Nordic peoples and their famous winter thermotherapy. The temperature in the shock pool is usually lower than that of swimming pools (about 7 degrees), and the goal is for a person to dive into the cold waters immediately after leaving a hot sauna or finishing a grueling strength training session. The benefits of this sudden change in temperature are the overall hardening of the body and specifically the cardiovascular and nervous systems. For the exerciser, this means that the muscles that were swollen during exercise contract, which helps immensely with their recovery and healing.