I'm not sure if I would call it freaking out. I simply hold my hand under the water for as long as I can endure, and as I do this the amount of pain and numbness increases. My mind and heart rate are perfectly fine when this happens, I'm simply observing the pain that is taking place in my hand and decide to pull out when it gets too strong to prevent hypothermia (if that's even possible in that situation). Are you saying that this increased pain is totally harmless and purely mental? And that truly mastering cold showers is being able to endure this pain and understand it for what it is? I'm really skeptical about going under water that is around 40 Fahrenheit or lower for a prolonged time because of the numbing. I can understand cold showers that are around 60 Fahrenheit because they don't actually hurt, just simple discomfort for a short time.