My answer to Can cold showers help the nervous system?
Answer by Connie b. Dellobuono:
Vagus nerve stimulation
- Diving Reflex: Considered a first rate vagus nerve stimulation technique, splashing cold water on your face from your lips to your scalp line stimulates the diving reflex. You can also achieve the nervous system cooling effects by placing ice cubes in a ziplock and holding the ice against your face and a brief hold of your breath. The diving reflex slows your heart rate, increases blood flow to your brain, reduces anger and relaxes your body. An additional technique that stimulates the diving reflex is to submerge your tongue in liquid. Drink and hold lukewarm water in your mouth sensing the water with your tongue.