A cold shower allows you to do just that, face your demons, every single time you step into a shower. As soon as the cold water turns on, your brain will instantly tell you to run from the pain.
Get out. Run, run, run! I haaaaate this. Find safety now. You are dying.
To remain in the cold, you will have to tell yourself, "don't run away, accept what is, don't try to fight it by tensing up or squirming, just let it be." If you remain calm and neutral, within a few seconds, you'll find that everything is…ok. You're still cold, but you're alive.
Bring yourself into awareness of this fact, and realize that you're not dying; you're not in danger; you're just experiencing something out of your comfort zone. And if you don't panic or try to escape the feeling, everything will remain as it is, and eventually, you will be able to transcend it.
The same goes with painful emotions, thought, and events. If you try to fight them or run away from them, they will still be there waiting for you to step back into the shower. Only this time you will be more filled with fear.
However, when you accept them and see them for what they truly are, you will be able to move past them. Maybe even learn to enjoy them.
3. The power of your breath
The moment the piercing water strikes your back, your breath will become short and shallow.
This is the way a majority of people breathe, taking shallow, short breaths without realizing it. The problem is that unconscious breathing can cause heightened levels of stress and discomfort.
If you want to stay in the cold shower for longer than a couple of seconds, you will have to remind yourself to breathe normally. Inhale for 5 seconds. Hold for 5 seconds. Then exhale for 10 seconds.
You can take this same breathing practice with you to work or any other stressful situations. It will help you calm down by activating the parasympathetic nervous system. Also, it gives you a chance to find space between the stimulus and your response to it.