Vey inteeresting read. Although I suspect there are some people for whom this practice might lead to serious health compromise, such as heart patients, I cold see a wide range of benefitts for most poeple in average health from just taking icy cold showers (i'm physically handicapped from neuro disease, so I won't be doing any plunging). I also don't know if I have the balls to try it, but I may consider looking further into the method if I feel so led.